Reloading For 7mm Rem Mag

[elkhunter11]

Originally Posted by Dean2

Take the load that makes the smallest groups, assuming you have one in the 1 MOA range, and play with the COAL. My bet is you will find a spot where the groups shrink a whole bunch.

That is what I would be doing. I would start at about .010" off of the lands, and increase this distance in .005" increments.

[Pioneer2]

Color the seated bullet in a case with no powder or primer with a Sharpie longer than it needs to be. Chamber and check for marks where it is touching the rifling ,color again and seat a little deeper.Repeat until it isn't touching and still fit and cycles in the magazine.....tight groups.........Harold

[markg]

Originally Posted by Dean2

Take the load that makes the smallest groups, assuming you have one in the 1 MOA range, and play with the COAL. My bet is you will find a spot where the groups shrink a whole bunch.

Normally i would do that but with the Tikka's we are limited by our magazine length. The person in our group that shoots a Sako doesnt. We have him backed about .020 off the lands. Thanks for the adivce and i appreciate were your going with that.

Anyone know if there is another magazine (aftermarket) that would help with our problem?

[Salavee]

Originally Posted by markg

I'm glad you mentioned this. We ran into the same problem. A group of us are reloading together, 3 shoot Tikka and one shoots Sako. We did a Coal test on all three with them all being within a thousandth of each other. We made some ammo and the cartridges wouldn't fit in the Tikkas. We had to go back and seat them deeper.

FWIW, I had a similar issue seating Accubonds in my .35 Welen. I wanted to seat out further than the mag would allow. With my trusty Dremal and a cut-off wheel I carefully cut the .190 tips off flush with the jacket. This allowed for the necessary mag room as well as some bonus powder capacity. Probably not the best choice for XLR but out to 200 yds .. no difference in POI. I didn't check beyond that range.

[Dean2]

Originally Posted by markg

Normally i would do that but with the Tikka's we are limited by our magazine length. The person in our group that shoots a Sako doesnt. We have him backed about .020 off the lands. Thanks for the adivce and i appreciate were your going with that.

Anyone know if there is another magazine (aftermarket) that would help with our problem?

Longer isn't always better. I have had a lot of bullets/loads that actually shot best a long ways off the lands, particulalry Barnes. With the Tikka I would start at max mag length and work shorter. My Tikka in 338 Federal has about .18 jump with 180 grain TSX and it shoots best with that much jump. I can seat them further out and still fit the mag but they don't group as well.

[Pathfinder76]

Originally Posted by elkhunter11

That is what I would be doing. I would start at about .010" off of the lands, and increase this distance in .005" increments.

If 0.005 makes a difference I want nothing to do with it or at least count it for what it is. Nothing to write home about.

[elkhunter11]

Originally Posted by Dean2

Longer isn't always better. I have had a lot of bullets/loads that actually shot best a long ways off the lands, particulalry Barnes. With the Tikka I would start at max mag length and work shorter. My Tikka in 338 Federal has about .18 jump with 180 grain TSX and it shoots best with that much jump. I can seat them further out and still fit the mag but they don't group as well.

I have used the TSX/TTSX in both the 7mmremmag, and in the 7mmstw, and I ended up at between .030" and .070" off of the lands in all rifles. With the Accubond and Ballistic Tip, I ended up at .010" to .020" in all rifles that were not limited by magazine length, and as much as .080" due to magazine limitations . Of course every rifle is different,so someone else might see different results.

[markg]

Starting to try some of this Enduron Powder IMR 7977. I will let you all know how the results on this one turn out. Anyone else have any feedback on it? Seems you have to load the case to capacity with this powder.

We got the 4350 standard deviation to be respectable 10-20 fps on 5 shot groups. We were shooting 65 grains which is pretty hot for this powder/cartridge and we were getting velocities up near 3100 fps. No obvious pressure signs. No good groups though.

[molly09]

Originally Posted by Cowtown guy

Those numbers are for their gun and conditions. Yours may be totally different.
Secondly 63 is their max load. DO NOT START THERE. Just because it is safe for them, don't assume it is safe in yours. They list a minimum. Start there. Work up slowly.
Next, if you are chasing accuracy, and by the bullet choice I am assuming that LR accuracy is your end strategy, don't get all hot and bothered with the speed. At the end of the day if you are shooting over 400 yards you are cranking dials. Does it really matter if it is 38 clicks or 41 to hit a 500 yard target? Chase the accuracy first. If speed follows safely then that's a bonus of sorts.
Last, many, many 7 Rem Mags seem to really love the 4831 powders. Again yours may not but they seem to really like each other.

try 61.5 4831 154 hornady I have the same gun. don't start with max load.

[elkhunter11]

Originally Posted by molly09

try 61.5 4831 154 hornady I have the same gun. don't start with max load.

One thing that I have learned over the years, is that the make and model of firearm often means little. I have seen rifles of the same make and model, that were only a few serial numbers apart, prefer very different loads. That is what makes handloading such a challenge.

[markg]

Originally Posted by elkhunter11

One thing that I have learned over the years, is that the make and model of firearm often means little. I have seen rifles of the same make and model, that were only a few serial numbers apart, prefer very different loads. That is what makes handloading such a challenge.

It's hard to understand why but every rifle is unique they use the same materials ext but each has a personality of its own.

[Dieselj19]

160 gr sierra boat tail 60grains imr 4350 and a standard primer

[markg]

I was able to shoot some test loads of 7977 today. I was shooting my Tikka T3 7mm Rem Mag riding in a GRS Berserk stock. Optics are Vortex Razor HD II 4.5x27x56

I went with the 150 grn Accubond Long Range bullet. I am using CCI 250 mag primers and Nosler Brass. COAL (3.444) is limited by my magazine, i am a bit further off the lands then i would choose to be. So far i haven't had great results with IMR 4350 IMR 7828.The 4350 produced the highest velocities.

Today was a different story. When i started this project i was looking for a load that was sub MOA and over 3000 fps. The 7977 with a charge of 70 grns produced an average velocity of 3012 fps with a standard deviation of 19fps and a group size of .542 centre to centre. Happy Days!!! I also tried a load of 70.3 grns of 7977 it produced an average velocity of 3058 fps and a standard deviation of 26.87 and group size of 1.11 inches

I am pretty excited and encouraged by these results. I think i may be in the ball park for my keeper load. Ill need to do some more testing but i finally found a combination that works and meets my parameters. The fact that the 7977 is supposed to be temp. insensitive is a huge bonus.

[Throttle_monkey1]

Good to hear! You gotta love it when it comes together. Are you going to try to find another accuracy node higher up in the load range or keep it where it's at?

I finally got the 150 ABLRs shooting tight as well. Mine was a rifle issue though.

[JD848]

Originally Posted by Dick284

A stout load of H1000 and 160 Accubond's yielded 2950 in a 7RM I once owned. Accuracy was pretty darn good.

One of my best loads with a 160,can't go wrong.

[markg]

I bought a can of Retumbo today and i am going to try that also. I cant seem to find anymore 7977

[waterhaulerhunter]

I'm pushing the 160 accubond to 2910 with a good load of H 4831sc. I could push it faster but accuracy dropped off. Getting about 3/4 Moa out to 450 yds.

[markg]

I finally get a load that I think im close on then i run out of materials. Grrrr

[markg]

I shot some of the Retumbo yesterday. It didnt perform as well as the 7977 using the 150 Accubond long Range bullets. It grouped nice but the velocities were under 3000 fps with 70.grs of powder. The 7977 were around 3050 fps with 70 grs.

[Throttle_monkey1]

Originally Posted by markg

I shot some of the Retumbo yesterday. It didnt perform as well as the 7977 using the 150 Accubond long Range bullets. It grouped nice but the velocities were under 3000 fps with 70.grs of powder. The 7977 were around 3050 fps with 70 grs.

Can you get anything faster? I'm running reloader 17 for the 150 ABLR. It's almost identical to 4350 in burn rate and I've settled on around 3220 fps.

[elkhunter11]

Originally Posted by markg

I shot some of the Retumbo yesterday. It didnt perform as well as the 7977 using the 150 Accubond long Range bullets. It grouped nice but the velocities were under 3000 fps with 70.grs of powder. The 7977 were around 3050 fps with 70 grs.

So are you seeing pressure signs if you go above 70gr? The Hodgdons data lists a max of 72.5gr with Retumbo and a 150gr Nosler bullet.


http://www.hodgdonreloading.com/data/rifle

[markg]

No Pressure signs so i could load it a bit hotter. I was happy with the size of the group

[elkhunter11]

Originally Posted by markg

No Pressure signs so i could load it a bit hotter. I was happy with the size of the group

If the accuracy is good, work the load up a couple of grains and see what happens. If you make it to 72 gr with no pressure signs, and the accuracy holds up, you should pick up another 100fps or so.

[markg]

I was out again today ( i know i need to get a life) i had some 4350 that we had loaded quite hot and i was nervous to shoot it on a hot day. Nosler has posted there max load at 63 yrs of imr 4350. I had no pressure signs at that load and have gone higher due to the fact my velocity is a lot slower then there post of 3248.

Todays load is 66 Grs of imr 4350 Nosler 150 Accubond LR produced my best velocity, group size and standard deviation.

Velocity avg 3149
Standard Dev 2.82 (best ever)
Group size on 4 shots 0.521 (had a flyer)

I must confess that my bolt was a bit sticky on 3 of the 5 rounds i shot. I have posted a photo of the primer on one of the rounds and I'm not sure if its been flattened.


Please do not try in your rile as i slowly built up to this in small safe steps.

[elkhunter11]

Originally Posted by markg

I was out again today ( i know i need to get a life) i had some 4350 that we had loaded quite hot and i was nervous to shoot it on a hot day. Nosler has posted there max load at 63 yrs of imr 4350. I had no pressure signs at that load and have gone higher due to the fact my velocity is a lot slower then there post of 3248.

Todays load is 66 Grs of imr 4350 Nosler 150 Accubond LR produced my best velocity, group size and standard deviation.

Velocity avg 3149
Standard Dev 2.82 (best ever)
Group size on 4 shots 0.521 (had a flyer)

I must confess that my bolt was a bit sticky on 3 of the 5 rounds i shot. I have posted a photo of the primer on one of the rounds and I'm not sure if its been flattened.


Please do not try in your rile as i slowly built up to this in small safe steps.

Given that the bolt is sticky, and it is cool out, I would back off two full grains, as the pressure will increase in warm weather. In fact the cool weather is likely why you made it to 66gr before you saw pressure signs.

[catnthehat]

You are likely over pressure now for that rifle if the odd one is sticky .
I would back it off a bit to be safe - wouldn't want to stick s case in the field or worse , have a case split or blow s primer and vent gasses through the back of the gun!
Cat

[markg]

I have a question for both of you. Do you think the accuracy was a result of the velocity? I was thinking of switching to normal accubonds at 140 yrs and they have a velocity up near what i got with these 150?

[catnthehat]

No, accuracy has far more to do with bullet jump than anything else .
Cat

[elkhunter11]

Originally Posted by markg

I have a question for both of you. Do you think the accuracy was a result of the velocity? I was thinking of switching to normal accubonds at 140 yrs and they have a velocity up near what i got with these 150?

That is impossible to predict, since you would be changing both the bullet weight, and the bullet style, which are usually more of a factor than a small change in velocity. The change in bullet weight and bullet style might improve the accuracy, or it might degrade the accuracy, by changing the harmonics of the load. As to velocity, some loads will maintain the accuracy over a fairly wide velocity range, and some loads are quite sensitive to changes in the velocity. I would drop the powder charge back two grains and see what happens to the accuracy. If it stays accurate, then the load is not sensitive to changes in velocity/powder charge, if the accuracy changes significantly, then the load is sensitive to changes in the velocity/powder charge. Loads that are not sensitive to changes in the velocity/powder charge, are usually not sensitive to changes in temperature, which is desirable in a hunting load that might be used at +20 or -20 degrees.

[Throttle_monkey1]

Originally Posted by markg

I was out again today ( i know i need to get a life) i had some 4350 that we had loaded quite hot and i was nervous to shoot it on a hot day. Nosler has posted there max load at 63 yrs of imr 4350. I had no pressure signs at that load and have gone higher due to the fact my velocity is a lot slower then there post of 3248.

Todays load is 66 Grs of imr 4350 Nosler 150 Accubond LR produced my best velocity, group size and standard deviation.

Velocity avg 3149
Standard Dev 2.82 (best ever)
Group size on 4 shots 0.521 (had a flyer)

I must confess that my bolt was a bit sticky on 3 of the 5 rounds i shot. I have posted a photo of the primer on one of the rounds and I'm not sure if its been flattened.


Please do not try in your rile as i slowly built up to this in small safe steps.

Hey Markg, your primer looks good, but if you had sticky bolt lift you are too hot. How sticky was it? Were the sticky rounds the later ones fired in a hot gun?

If you switch to a 140 accubond you might have to start all over. The 150 ABLR has a short bearing surface, the bearing surface in the 140 may be longer. The longer the bearing surface on a bullet, the more friction it has, which will cause pressure to spike. Lots of jump into the lands will reduce pressure. Shorter bullets can be seated further out which will reduce pressure.

With my rifle, once I got the barrel channel completely floated which got rid of my flier, I had an area within the top of the load range that had the same POI and accurate groups within one grain. Eg 64.0 64.3 64.6 and 65.0 grains gave me great groups and velocity. This was the optimal charge weight for my rifle with that powder, bullet, length etc. so I settled in the middle of that one grain zone.

I would play around within that area where you shot that great group with 4350 and see how your accuracy is if you drop off half a grain, and then a full grain. You might be a tad hot where you are, but personally I wouldn't drop a full two grains yet. I'd try to safely stay within the node you're at. Others will give you different opinions, and they're not wrong. I would just do it this way because I know how frustrating it is burning through reloading components.

Good shooting btw!