Allen Mag Shooters Group

[wadedc]

Took the .338 AM out to 1000 for the first time today. It was gusty today but after a sighter I got a 10" 3 shot group at 1000. The 300 SMK goes through my 1/2" steel like butter at 1000 yds. I shot 135, 136, 137, 138, 139 and 140 grains with the 300 SMK and then 2 285 tsx loads all into 1 " at 100yds. Pretty good for all different loads.

 

[royinidaho]

Took the .338 AM out to 1000 for the first time today. It was gusty today but after a sighter I got a 10" 3 shot group at 1000. The 300 SMK goes through my 1/2" steel like butter at 1000 yds. I shot 135, 136, 137, 138, 139 and 140 grains with the 300 SMK and then 2 285 tsx loads all into 1 " at 100yds. Pretty good for all different loads.

All bullets will shoot well, no doubt. The trick is to settle in soon enough on a load, do the drop chart and go to harvesting stuff.

 

[wadedc]

Load development done. I am going with 135gr under the SMK @3200fps and 130gr under the TSX @3250fps. Kirby warned me about the barnes creating more pressure even with a lighter bullet and he was right!

 

[car2go4]

btt for great thread

 

[esshup]

Time to bring an old thread back to life.

My first full house load in COW fireformed cases with a 175g SMK is running (depending on ambient temps, 30°F to 95°F) 3400 to 3490 fps - 109.3g WC-872. Accuracy at 300 Yds is hovering right around 1/4 moa if I watch the wind and concentrate.

Loaded the same combo in the cases again after the first full house load and they seem to be printing around 2+ moa at 1050 yds. when shot into a dry hillside. Haven't done any concrete paper/steel testing, nor run them over the chrono yet.

Thoughts?

 

[royinidaho]

Loaded the same combo in the cases again after the first full house load and they seem to be printing around 2+ moa at 1050 yds. when shot into a dry hillside.

Thoughts?

Hmmmm, I've not had much if any accuracy changes from first fire forming, post COW fire formed or fully fire formed cases in two 270 AM barrels.

Didja try them @ 300 before going to 1050?

 

[esshup]

No, I didn't try them @ 300. I loaded rounds and left for a Cow Elk Hunt in Co. I brought 20 fireformed loads and 20 post fireformed loads. In verifying the rifle after transport I saw the differences. Didn't see an Elk the whole trip.

There's the possibility that I'll be back out there before the tags expire on 12-31, but don't want to fire the rifle before then as I still have 15 of the first full house rounds to go, and can use those on the hunt. I'll just verify after travel again.

I'll do more testing after 12-31 @ 300 Yds. and run them over a chronograph at the same time.

 

[Buffalobob]

WC 872 can burn very dirty if pressures are not up high enough and even then it seems to be dirtier than other powders. I and others have found that accuracy in the 7 AM degrades after 15-20 rounds and you must clean it to regain accuracy. Just tremendous amounts of powder being burned in that small diameter of a barrel. Use a carbon ring remover such as JB or Iosso.

 

[esshup]

Thanks Bob, I noticed the same thing on the round count. One good thing about the barrel is that it cleans up really quickly. Using Montana Extreme Copper Killer and Hoppes Elite, nylon brush and nickel plated jags.

This is close to the upper limit, sometimes I was getting a hint of drag on the base of the shell with 110g of powder and temps in the upper 80's with everything in the shade. Going from 110g to 111g only increased velocity by 20 fps, not the usual 50 fps that I was seeing with 1.0g increase in powder.

 

[TheFishBox]

I know this is an old thread but I am curious as to what the barrel life has been on some of the allen magnums since they have been out for a while now.

 

[esshup]

I think a lot will depend on how well you take care of the barrel (i.e. don't let it get hot, etc., etc.)

 

[royinidaho]

I know this is an old thread but I am curious as to what the barrel life has been on some of the allen magnums since they have been out for a while now.

My 270 AM went for ~950 rounds before it fell out of grace. All shots were at the top end of things plus there was a ton of experimenting. I didn't abuse it but didn't cut it any slack either.

Rebarreled in 270 AM. This one will last much longer in years and more shots.

 

[TheFishBox]

Thanks for the info what are some of the pros cons on the 270 allen vs your 375 allen mag if you don't mind posting. Does anyone else have experience they would like to share about there allen magnums like if you would go with this extreme of a caliber and things like brass life bullet performance powder availability.

 

[esshup]

I've got a 7mm AM and I view it as another tool to use in the toolbox for specific hunting applications.

I purchased enough powder/primers/bullets to last for close to the life of the barrel, so I don't have to worry about availability. It's definately not a target rifle where you can shoot 50-100 rounds per day.

I don't know if it's necessary, but I anneal before every loading. I had some issues with neck to shoulder splits on cases that sat for a few years after fireforming. Annealing solved the problem.