Finding the Accurate Load

[Don_Parsons]

My friend sent me this last summer so I could "slowly" get up to speed. Scroll down on the page for the read.

http://www.realguns.com/archives/093.htm

I have other things to address before attempting this stuff, very interesting mind you.

Don

[elkhunter11]

Originally Posted by lclund1946

While it is usually much easier to find Good Loads with the bullet close to the lands most Saami and many Wildcat cartridge designs do not lend themselves to seating close to the lands.

The 20 Tactical is a 223 rem case with the OAL shortened and shoulder bumped back in an attempt to get a longer neck, like the 204R, and have the bullets fit in a Saami Standard 0.226" magazine. The FreeBore was reduced to 0.045", in an attempt to reach the lands with the v-Max bullets, but the Throat angle was left the same as the 204R. Then in an attempt to get the case to hold a similar amount of powder the case is blown out at the shoulder by about 0.014". This actually resulted in a case that holds about 0.7 grains less RS X-Term behind the 40 V-Max but can only get 3700 fps by increasing the pressure to 63,000 PSI. Accuracy is not good, especially in a 1/2" twist barrel until these pressures are reached. Here is a kink to a discussion by some of the boys who gave me a hard time on this site. Notice the confusion??? http://www.saubier.com/forum/showthread.php?t=28859

And here are typical groups fired with my 20 Tactical, with the 39gr Blitzking seated .010" off of the lands. The COL is way over 2.26", yes that is 2.26" not .226", and they function just fine in the magazine, with clearance to spare. And with the longer throat, and longer COL, the effective case capacity is actually increased slightly, as compared to short throating and using a shorter COL. Notice that there are two different loads, to demonstrate that I can vary the load by 200fps with similar accuracy. These are three shot groups, not five, because at the time the 39gr Blitzkings were in short supply. And some of these groups actually are sub 1/4 moa groups, with no fliers or sighting shots.

[densa44]

As I understand the physics of ballistics once the bullet leaves the barrel there is only gravity acting on the bullet, wind too I suppose.
So the objective of the exercise for the re-loader/shooter is to find the mv where the bullet leaves the barrel at one of the 2 nodes thus eliminating an up or down vector for the bullet.
Once we find that mv. the task is to produce ammunition that is identical shot to shot.
What I have been doing is to fire form my cases, work on loads until I find a node at close to maximum velocity, load up lots of ammo and then practice.
My targets are about as good as the ones I see here.
I still find that no matter how good my shells are, that waving the barrel around still causes most of my problems.
I note in the post that IMR 8208 shows very good results, and I'd like to know more about that. I have never tried it but am now very interested.

[markg]

We definitely have some people on this forum that are excellent shooters

[lclund1946]

Originally Posted by elkhunter11

And here are typical groups fired with my 20 Tactical, with the 39gr Blitzking seated .010" off of the lands. The COL is way over 2.26", yes that is 2.26" not .226", and they function just fine in the magazine, with clearance to spare. And with the longer throat, and longer COL, the effective case capacity is actually increased slightly, as compared to short throating and using a shorter COL. Notice that there are two different loads, to demonstrate that I can vary the load by 200fps with similar accuracy. These are three shot groups, not five, because at the time the 39gr Blitzkings were in short supply. And some of these groups actually are sub 1/4 moa groups, with no fliers or sighting shots.

As I have told you countless times, over the years, I know that the magazine in your Cooper will hold a much longer COL than the Saami Standard. What you have never offered is what the actual COL is with the 39 BK seated 0.010" off the lands. I know that the extra COL gives you about 0.2 grains more powder over a bullet seated to 2.26". However the 294R holds about 0.5 grains more than that, with bullet seated to Saami specs, and for some reason the extra powder results in a Velocity/Pressure decrease. Like I posted earlier your 3700 fps load is likely pushing 63,000 PSI, much like the RS X-Term load which burns very similar in a similarly confined space. This is because the X-term is a ball powder and much denser than RL 10X. I know that this pressure has become acceptable, in spite of the 223 case being Saami Rated at less than 58,000 PSI, likely because the 20 Tac does not have an accuracy node lower than that. However I still prefer to run less than that in the gopher patch.

Your 3900 fps , as I have pointed out on numerous occasions, is well above 63,000 PSI and a "Safe In My Rifle" load just as the 21.7 grain RL 10X load was on a cool day in my 20 EXTREME. While 20.3 gains gives a "Good Safe Load" at 3650 , for all rifles, 21.5 grains blew a primer at 3850 fps on a hot day under sustained fire, just as I suspected, and just what I expect from your hot load. By the way it is not that hard to get Small groups with RL 10X if you run the pressures up to 60,000 PSI in these small cases. This pressure ladder shows that but is the primer flow and PR Expansion told me what to expect.
[IMG][/IMG]

The trick is to get more than one load like this and believe me I have many that fit.
[IMG][/IMG]

I may be a bit off but this is what a 39 BK would look like when seated to the lands in a 20 Tac Fire form Load and a fire formed load. I know you didn't have to Fire Form your Dakota brass but that is not available anymore. People are reporting problems with donuts forming, especially with Lapua M brass, due to the neck being formed into the shoulder. This is not a problem with the 20-223 EXTREME due to the design improvements.
[IMG][/IMG]

204R with 39 BK to lands:
[IMG][/IMG]

20 EXTREME & 20-223 EXTREME with 39 BK seated to the lands.
[IMG][/IMG]
Typical groups at 3500 fps with IMR 8208 in various rifles:
[IMG][/IMG]
[IMG][/IMG]
[IMG][/IMG]

"Good Safe Load" with a full case of IMR 8208 in Winchester and LC Nato Brass.
[IMG][/IMG]

I set out to design a 20 caliber cartridge that that would match a 22-250 Factory 55 HP. It had to be designed to run the 39/40 grain bullets seated properly in the neck when seated to the lands and fitting in a 223 Saami spec Magazine. It had have the proper capacity to run 32-40 grain bullets to near 204R velocity with 95-100% case fill with low pressures. All of these things leave a bit to be desired in the 20 VT, 20 Tac and 204R. I never made any claims that it was superior to any of these cartridges but obviously you believe it is or you would be happy for me.

The 20-223 is very easy to form from 223 brass as all you have to do is run through the 20 EXTREME dies, in one pass and trim if you want them uniform. Lapua Match brass has to be neck turned to be safe although it will fit in the neck. No fire forming of new brass and the fact that loaded rounds easily fit in a 223 Saami magazine when seated to the lands, make this cartridge more desirable than the 204 R or 20 Tac in my view. However it is not really an improvement over the 20 EXTREME unless you want to run 223 and once fired brass has to be annealed and trimmed like the 20 Practical. Unlike the 20 EXTREME the 55 Berger is too long and would have to be run single shot like I did the 20 Practical to make it perform. However it may be a perfect fit in your Cooper magazine??

[elkhunter11]

Originally Posted by lclund1946

As I have told you countless times, over the years, I know that the magazine in your Cooper will hold a much longer COL than the Saami Standard. What you have never offered is what the actual COL is with the 39 BK seated 0.010" off the lands. I know that the extra COL gives you about 0.2 grains more powder over a bullet seated to 2.26". However the 294R holds about 0.5 grains more than that, with bullet seated to Saami specs, and for some reason the extra powder results in a Velocity/Pressure decrease. Like I posted earlier your 3700 fps load is likely pushing 63,000 PSI, much like the RS X-Term load which burns very similar in a similarly confined space. This is because the X-term is a ball powder and much denser than RL 10X. I know that this pressure has become acceptable, in spite of the 223 case being Saami Rated at less than 58,000 PSI, likely because the 20 Tac does not have an accuracy node lower than that. However I still prefer to run less than that in the gopher patch.

Your 3900 fps , as I have pointed out on numerous occasions, is well above 63,000 PSI and a "Safe In My Rifle" load just as the 21.7 grain RL 10X load was on a cool day in my 20 EXTREME. While 20.3 gains gives a "Good Safe Load" at 3650 , for all rifles, 21.5 grains blew a primer at 3850 fps on a hot day under sustained fire, just as I suspected, and just what I expect from your hot load. By the way it is not that hard to get Small groups with RL 10X if you run the pressures up to 60,000 PSI in these small cases. This pressure ladder shows that but is the primer flow and PR Expansion told me what to expect.
[IMG][/IMG]

The trick is to get more than one load like this and believe me I have many that fit.
[IMG][/IMG]

I may be a bit off but this is what a 39 BK would look like when seated to the lands in a 20 Tac Fire form Load and a fire formed load. I know you didn't have to Fire Form your Dakota brass but that is not available anymore. People are reporting problems with donuts forming, especially with Lapua M brass, due to the neck being formed into the shoulder. This is not a problem with the 20-223 EXTREME due to the design improvements.
[IMG][/IMG]

204R with 39 BK to lands:
[IMG][/IMG]

20 EXTREME & 20-223 EXTREME with 39 BK seated to the lands.
[IMG][/IMG]
Typical groups at 3500 fps with IMR 8208 in various rifles:
[IMG][/IMG]
[IMG][/IMG]
[IMG][/IMG]

"Good Safe Load" with a full case of IMR 8208 in Winchester and LC Nato Brass.
[IMG][/IMG]

I set out to design a 20 caliber cartridge that that would match a 22-250 Factory 55 HP. It had to be designed to run the 39/40 grain bullets seated properly in the neck when seated to the lands and fitting in a 223 Saami spec Magazine. It had have the proper capacity to run 32-40 grain bullets to near 204R velocity with 95-100% case fill with low pressures. All of these things leave a bit to be desired in the 20 VT, 20 Tac and 204R. I never made any claims that it was superior to any of these cartridges but obviously you believe it is or you would be happy for me.

The 20-223 is very easy to form from 223 brass as all you have to do is run through the 20 EXTREME dies, in one pass and trim if you want them uniform. Lapua Match brass has to be neck turned to be safe although it will fit in the neck. No fire forming of new brass and the fact that loaded rounds easily fit in a 223 Saami magazine when seated to the lands, make this cartridge more desirable than the 204 R or 20 Tac in my view. However it is not really an improvement over the 20 EXTREME unless you want to run 223 and once fired brass has to be annealed and trimmed like the 20 Practical. Unlike the 20 EXTREME the 55 Berger is too long and would have to be run single shot like I did the 20 Practical to make it perform. However it may be a perfect fit in your Cooper magazine??

Actually I did post the COL of my load , as well as the interior length of the Cooper magazine. , but I am away from home, and don't have those numbers handy. I can say that the COL is way over the SAAMI magazine length, not just slightly longer, so .2 of a grain is likely not realistic. As for the Dakota 20 tactical cases, they were a one time run, but the run was for a very large amount, and they are still available. Prophet River still has stock and was processing an order today when I dropped in. As for you pressure estimates of my load, since you don't even know the COL, they are nothing more than guesses. I have measured case head expansion, and after five firings on a group of five cases, the primer pockets are still tight, which makes me quite comfortable with the load, under the conditions that I use it. I don't let the loads sit in the hot sun, and then fire load after load until the barrel is hot, and the rounds are sitting in a hot barrel heating up even more. For high volume ground squirrel shooting, I use my 17 hornet, because it is much more suited to that type of shooting than either the 20 tactical, or your 20Extreme.

[lclund1946]

Originally Posted by elkhunter11

Actually I did post the COL of my load , as well as the interior length of the Cooper magazine. , but I am away from home, and don't have those numbers handy. I can say that the COL is way over the SAAMI magazine length, not just slightly longer, so .2 of a grain is likely not realistic. As for the Dakota 20 tactical cases, they were a one time run, but the run was for a very large amount, and they are still available. Prophet River still has stock and was processing an order today when I dropped in. As for you pressure estimates of my load, since you don't even know the COL, they are nothing more than guesses. I have measured case head expansion, and after five firings on a group of five cases, the primer pockets are still tight, which makes me quite comfortable with the load, under the conditions that I use it. I don't let the loads sit in the hot sun, and then fire load after load until the barrel is hot, and the rounds are sitting in a hot barrel heating up even more. For high volume ground squirrel shooting, I use my 17 hornet, because it is much more suited to that type of shooting than either the 20 tactical, or your 20Extreme.

I did find a COL that you may have posted at 2.352" and did check with Prophet River regarding the Cooper Magazine and do know that 2.352" will fit and never did state otherwise as you have stated many times. I also talked to Clay, at Prophet River, a year or so ago and he told me that he had 100 in stock. He also said that the Dakota brass was not available anymore and that brass could be formed from 223. I am waiting to hear back from one of their salesmen who knew nothing about 20 Tac brass.

I have some information that I found online indicating that 20 Tack Dakota brass holds about 30.57 grains of H2O compared to fireformed Lapua 223 @ 30.28 grains and Winchester at 30.04 grains. I also know that forming from 223 requires a forming die, and run through a 20 Tac FL die before fire forming. I also know that Lapua 223 brass should be neck turned and that donuts are a problem, especially in the Lapua Brass. This is something potential 20 Tac owners should know and be made aware of the Ramshot pressure tested loads. I initially posted that your 3700 fps load with 10X was likely safe in all rifles but suggested that your 3900 fps load was likely to cause problems in hot temperatures, under sustained fire, as this powder is very temperature sensitive and varies quite a bit from lot to lot. When I suggested you test it under these conditions and then report it as a Safe Load you chose to begin your personal attacks against me which has become more of a crusade. You have made claims that I claimed that my 20 EXTREME was superior but I never did that either.

Thank you for informing us that you don't use this load under hot conditions as I suggested. That is all I ever wanted along with an opportunity to get together with you and compare notes but you chose not to do that and continue to try to undermine me for whatever reason. I did put together a drawing this morning and you were right in that seating the 39 BK past Saami specs adds about 0.8 grains of powder not 0.2. I also found that the Dakota Brass loaded this way holds about a grain more than the 204 R with bullet seated to Saami COL but it is only seated with 0.78" bearing surface in the neck.
[IMG][/IMG]

As you can see, based on 204R pressure tested data, extrapolated up it is quite possible that your load could get to 3900 fps and still be under 63000 PSI. If you were running this load with Rem 7 1/2 primers, in a CZ 527 like mine, I would expect primer flow to be 0.003 to 0.005" which is over Max in my rifles. Your chamber should measure 0.375" inches at the 0.200" Datum, and I would estimate that your brass will have expanded to near that with this load. The 3700 fps load would likely expand the PRby about 0.001", or leave at least 0.0005" chamber clearamce and there would defiantly be no CHE so primer pockets would last a long time.

My 20 EXTREME is great in the gopher patch with the 32/40 grain bullets running at just over 20 VT velocities. I gave up the 17's in favor of a 22 LR for close range and use the 20 if I want some explosive action or go to long range. I did appreciate your caution on a thread about the 17 Hornet running LiL Gun. That is what we need on these forums, more of this rather than this .

[lclund1946]

Originally Posted by densa44

I note in the post that IMR 8208 shows very good results, and I'd like to know more about that. I have never tried it but am now very interested.

IMR 8208 XBR is very temperature stable and works great in cartridges where H4895 is being compressed. It is slightly faster burning than H 4895 but does not fill the case so a given load may produce about the same pressures as the compressed load of H 4985.

A lot of BR shooters got the impression that IMR 8208 XBR was going to be the same as the discontinued IMR 8208 , made in Canada, that some SRBR shooters had bought up and began calling Thunderbird. They jumped on the BR bandwagon and bought up a bunch only to find that it was too slow to work great in the 6mmPPC with the 65-68 grain FB bullets that fit and worked best for SRBR. Here is an excerpt from a letter to Speedy Gonzales clearing that up and explaining what IMR 8208 was, "Just a note on Hodgdon's 8208. The 8208 that is being brought into the country is not being brought in for the benchrest market as most people believe. It is being brought into the country for military contracts and it just so happened that it worked in the PPC. It is being QC'd for those military contracts not for benchrest shooters. There is more money in the military side of selling powder. I work directly with the company using it for military applications. LT-32 is just the opposite. We developed this powder specifically for the 6mm PPC and it is QC'd in the 6mm PPC.

I can send you a sample if you would like.


Best regards,
Keith Anderson
Western Powders Ballistic Lab ". IMR 8208 Works great in the 223 and 204 Ruger and Hodgdon have pressure tested loads in their online manual.

Even before IMR 8208 was introduced at the 2010 Shot Show I had seen a report on tests done with it. I had been using the Hodgdon EXTREME 4895powder, Made In Australia, and found t]it a bit too bulky and slightly slower burning than optimal for the 40 grain bullets in My 20 EXTREME. When I discovered that it was nearly the same in kernel size and density as Benchmark and H 322, also EXTREME Powders, and just a bit faster burning than H 4895 I knew I it was the powder I had been dreaming about. I ordered 16# before it was released and took delivery in the summer of 2010. It is the perfect powder for the 39/40 grain bullets as a 95% load gets over 3500 fps and a near 100% load gets the 39/40 bullets to near 3360fps with no danger of over pressure under any condition.

The Hornady Manual show the 204R getting 3754 fps, with the 40 V-Max ahead of 27.3 grains of IMR 8208, and generating 56,000 PSI. As the 204 R holds about 2.9 gains more water, under the 40 V-Max, than the 20 Practical I thought stating at 25 gains. I shot the 5 shot ladder group shown over a MagnetoSpeed at 14 degrees Celsius. Shot #1 registered 3757, Shot #2 showed a 20 fps increase for 0.1 grain increase. Shots #3&4 showed no increase but piled on top of shot #2 which is what I am looking for when trying to find a good stable load. Shot #5 showed a significant pressure spike going to 3813 which resulted in a stiff bolt lift. I shot 3 More at the 25.1 grain load and they stacked on the second target. Buddy was estatic as his method of loading up to stiff bolt and backing off gave a "safe in my rifle" load at an average of 3776. We tested the 39BK at 25.6 grains and got stiff bolt lift, at 3859fps, so went down to 25.2 grains and got 3782 which is about what I expected. It takes about .1- .2 grains more 8208 go get the 39 BK up to the same velocity as the 40 V-Max. Just tried the 40 Nosler BT at the starting load and pulled the rest of the bullets. These are awesome loads for the "safe in my gun" hand loaders but I would back down at least another 1/2 grain or about 3700 fps. I estimate that these loads would be running near 65,000 PSI, on a hot day, under sustained fire.
[IMG][/IMG]
I found that H 4989 worked better with the 40 V-Max but did not try backing the 8208 load to see what it would do at 3650 to develop a "Good Safe Load" in the 20 Practical. I hope to do that with my 20-223 EXTREME and it looks like that should be at 23.9 to 24.1 grains. My 20 EXTREME does that with a full load @ 22.2 grains so really no advantage to the bigger case.
[IMG][/IMG]

[HW223]

Have you looked at a 20 ppc
Accurate powder shows a load of 29.2 gr of 2520, 40gr vmax at 3925 and only 57,925 for pressure.

[lclund1946]

Originally Posted by HW223

Have you looked at a 20 ppc
Accurate powder shows a load of 29.2 gr of 2520, 40gr vmax at 3925 and only 57,925 for pressure.

I have looked at the 20 PPC and it is a very efficient cartridge compared to the 20 Tac, 204R, 20 BR or anything bigger. It will run the 40 and 55 grain bullets easily to about the max that the bullets are designed to run and will certainly be easier to find a "good load" in than larger capacity cases especially if they are not designed to reach the lands.
It would certainly extend the range to about 600 yards on varmints compared to my 20 EXTREME. If I was looking for a longer range Varmint rig I would go to something that would push a 22 Cal ,90 grain Berger, to 3200 fps.

For a dual purpose gopher/coyote gun, to 500 yards, I would still prefer the 20 EXTREME for reasons I have already stated. As well it is more suited to the CZ 527 and other 222/223 actions, with Saami 222/223 bolt face and magazines, as it feeds great from them.

Here is what the 20 PPC would look like with the 40 V-Max loaded as per the Accurate load seated to the lands. It would be chambered with ZERO Freebore and a 1 deg 30 min throat.
[IMG][/IMG]

A 9" twist barrel would stabilize the 55 Berger which would look like this seated to the lands.
[IMG][/IMG]

[HW223]

I would give it .050-.070 freebore , allows more powder/velocity with no more pressure 29.2 grains fits without being compressed , in a good set up I’m confident that one would be able to turn it up if the bullet will stand it with zero primer flow or brass problems as we are way over that now with the 22 and 6mm stuff. Looks to be a fun winter project
Good read in Berger’s reloading book page 151 about antiquated saami limitations and how they limit the performance of modern potential.
Time to move into the 21st century.

[lclund1946]

Originally Posted by HW223

I would give it .050-.070 freebore , allows more powder/velocity with no more pressure 29.2 grains fits without being compressed , in a good set up I’m confident that one would be able to turn it up if the bullet will stand it with zero primer flow or brass problems as we are way over that now with the 22 and 6mm stuff. Looks to be a fun winter project
Good read in Berger’s reloading book page 151 about antiquated saami limitations and how they limit the performance of modern potential.
Time to move into the 21st century.

I thought that you might want to set it up so that you could run the 40 Berger to the lands and still have some bearing surface in the neck. You would have enough powder room to spin the jacket off and really blow up a coyote at 50 yards? If you want more freebore just do the TK design, that he shows in his book, as it has 0.463" freebore.
[IMG][/IMG]

With the 55 Berger you would have more than enough powder capacity to get to 3500 fps at 58,000 PSI and may get another 75fps at 63000 PSI. However you could push it even faster with a powder like H 322 and blow your gun up like some have reported with TK loads. What will it prove???

[HW223]

40 gr at 3950 would be just fine for gophers .050 freebore should be a nice fit .

[Jay Kyle]

https://i.imgur.com/0iHSZIj.gifv


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