375 Allen Mag vs these cartridges

[ragnarok]

I bought my 375vm2 3 years ago, and i e shot 7-800 rounds with it, tested all kinds of bullets at various distanse, best bullet combination so far is the cutting edge 377gr mtac bullet with 164gr og vith20n29 powder this gives 3325fps and no pressuresigns, and is extremely accurate. Ive tested also 350gr sierra, but they foul to much thing its because of speed i dunno, tried do down load them to about 3250fps, but that gave me underpressure in the casing with h50bmg. Also tested the woodleigh 350vld wich are very good brass solids, loaded mildely to 3300fps and the second most accurate bullet ive shot is the 352gr gs custom, witch also is extremely accurate, thats the one ive shot mostly because i can get them very easy

Ive reloaded the same cases maybe 10-15 times and no issues with them, i anneal every time. ive got a 10twist barrel on mine

Any one tried to coat their 350 sierras with this boron coating?

 

[royinidaho]

Any one tried to coat their 350 sierras with this boron coating?

Yep I've done that.

350 SMKs and SMKs modified to 353 Brass Tipped to 3335, kind of loafing along with US-869 and H-50 BMG. HBN on these, in this particular barrel greatly decreases bore cleaning efforts. So far, only limited rounds w/HBN and a bore that doesn't hardly copper foul, copper fouling has been all but eliminated.

What is your twist rate? CEBs go wonky for me at distance.

 

[ragnarok]

Sounds great, ill buy a kit and see how it turnes out then, ive gotta 10"twist, thanks for the reply

 

[royinidaho]

I bought my 375vm2 3 years ago, and i e shot 7-800 rounds with it, tested all kinds of bullets at various distanse, best bullet combination so far is the cutting edge 377gr mtac bullet with 164gr og vith20n29 powder this gives 3325fps and no pressuresigns, and is extremely accurate.

I verified my 375 AM at precisely 1 turn in 10 inches. Why is this same bullet 377 MTAC not stabilizing for me beyond 7XX yards?

What is your elevation?

My elevation is 4488 feet with a typical Baro press of 25.5 inches HG.

Stability Factor is well above 1.5 but less than 2.0.

SMK stability factor is above 2.5 and are stable to the horizon or beyond.

 

[ragnarok]

Ive been shootin these at about 600ft above sealevel, cant remember the pressure, i had a 0.5moa group size 5 shots from 200m out to 1250m, i shot a 5 shot group at 1225 wich was a good 6".

I dunno why they are not stable in yours?

 

[cowboywhorses]

Awhile back I read that Cutting Edge bullets may need a certain bore diameter? Now each barrel maker may have different views on this. But you could give CEB a call and see what is needed to stabilize that type of bullet . Just food for thought.

 

[Wachsmann]

I've been reading through theses post alot. What is the expected barrel life on these 375's..Around 800 to 1000 rounds? Also it seem most the calibers want to run in the 3200fps or faster or the accuracy fall off.

 

[royinidaho]

I've been reading through theses post alot. What is the expected barrel life on these 375's..Around 800 to 1000 rounds? Also it seem most the calibers want to run in the 3200fps or faster or the accuracy fall off.

I burned out, and quite severely, one 270 AM barrel in 900 rounds and another in 600 rounds.

I fully expect the 375 AM, even at 3300 FPS, to last on the order of 3000 rounds.

Having said that I also expect it will one of the next generation of family that will know for sure.