I'm getting a new barrel it is drilled for 7mm but not chambered. I was going to go with the 7 rum but from I have read and heard that is a barrel eater so I was wondering what is another good cal for long distance 1000yrds plus in the 7mm and is it a barrel eater as well
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Gunsmithing What 7mm cal to chamber a new barrel
- Thread starter Erik Akromid
- Start date
7mm STW. Brass can be made from several calibers. As for barrel burning, Most of today's barrels will withstand far more heat and pressures than in the past.
His rifle is a 7mmRUM.
7mmRM is still a good performer with decent barrel life. My last one was pushing 176 grain bullets at 3040 fps out of a 26" barrel.
7mmRM is still a good performer with decent barrel life. My last one was pushing 176 grain bullets at 3040 fps out of a 26" barrel.
I use a .280 Ackley Improved. Using the Berger 168 grain VLD and 59 grains of RL 19, I get 2850 fps out of a 25" Schneider barrel. That's good for about 22 MOA drop at 1000 yards, and less than 2 MOA windage at a full value 10 mph wind. Recoil is a lot less than the 7mm Mag I used to shoot, and the barrel life is much better than any magnum I know of.
the .280AI is as good as it gets in 7mm with any kind of moderation. you have to go quite a bit bigger and use very expensive and sometimes "unobtanium" brass to do it. mine would push the 162 amax to 3100fps in a 27" barrel.
chuck
chuck
It's a factory remington sendora long action if that helps twist rate on the new barrel is a 1-8
An improved version of the .284 Win designed by Bill Shehane if my memory serves me right. Just wanted to throw it out there as a possible choice. It's getting a decent following as of late. Personally I like the aforementioned 280 Ackley and will likely have on in my box of tools someday.
Thanks Erik, was just thinking of my next build in a 284 Win. Switching most of my calibers over to 7mm
You won't regret the .280 AI. It's accurate, easy to feed, and case prep is a snap because the cases hardly stretch at all. It is very good at cheating the wind, and it maintains a good bit of energy at extended ranges as well. My .308 175 grain SMK's get to 1,000 with about 1250 ft/lbs. The .280 168 gr. Bergers get there with about 1,700 ft/lbs.
I don't. Mine go at 2850 fps. I have found that the G7 drag model much more closely predicts my VLD bullets' actual flight path at longer ranges. My earlier post compared the 1,000 yard results for both the .308 175 grain SMKs and the .280 168 grain Berger VLDs using the G7 drag model for both bullets in the Ballistic AE app. Using the G1 drag model for both bullets still shows significantly greater energy for the .280 AI: the 175 SMK's retain 556 ft/lbs at 1,000 yards, the 168 Bergers retain 895 ft/lbs -- about a 60% increase.
This is what I'm going to build. I really like the performance of the .280 AI. Plus it can fire standard .280 ammo out of the box to fireform it.
There's nothing wrong with a standard 280 either. I shoot 162 Amax's out of a 24.5" barrel at 2890. No pressure signs. No fire forming brass. If you really want to get them moving go with 7mm Rem Mag. You can't go wrong with either.
I made a chart to compare 7mm chamberings, holding the pressure at 65 kpsi and comparing distance to equal velocity.
Hornady 7MM .284 DIA 162GR BIG GAME POLY CARB TIP 28452bullets and moly coated them
Comparing cartridge performance at close to optimum powder choice and 65kpsi:
7mmT/CU ........................26.1 gr H335 2330 fps -471 yards
7-30 Waters ........................30 gr W748 2456 fps -395 yards
7mmBR ...........................31.2 gr W748 2510 fps -360 yards
7mm IHMSA .......................40.2 gr Re17 2704 fps -247 yards
7mm-08 .......................40.6 gr IMR4895 2789 fps -198 yards
7mm-08AckleyImproved .........43.6 gr Re15 2833 fps -171 yards
7x57mm ...........................44.6 gr Re15 2843 fps -165 yards
7x57mmAckleyImproved .........46.4 gr Re15 2873 fps -150 yards
284Win .........................50.0 gr IMR4350 2890 fps -172 yards
280Rem ............................53.5 gr H414 2961 fps -152 yards
7mm Rem short action ultra mag 55.5 gr Re17 3015 fps -73 yards
280RemAckleyImproved ........57 gr IMR4350 3019 fps -71 yards
7mmRemMag ......................68.2 gr Re22 3129 fps -15 yards
7mmRem ultra mag ............83.3 gr IMR7828 3130 fps -15 yards
7mmWeathMag ....................71.8 gr Re22 3170 fps +7 yards
7mmSTW .............82.2 gr Ramshot Magnum 3158 fps 0 yards
*The 7mm IHMSA, 7mm-08, 7mm-08AckleyImproved, 7x57mm, 7x57mmAckleyImproved, 280Rem, and 280RemAckleyImproved have 1889Mauser case heads [7.65x53mm parent] with large Boxer primer pocketsand 65,000 psi is a reasonable max pressure for handloads.
*The 7mmBR 1889 Mauser case heads [7.65x53mm parent, 6mmBR parent]with small Boxer primer pockets and could have gone to 80,000 psi:
*The 7mmRemMag, 7mmWeathMag, and 7mmSTW have a 1912 H&H case head[375 H&H parent] and could have gone to 70,000 psi.
*The 7mmTCU has a 1950 Rem case head [.222 Parent] with small Boxerprimer and could have gone to 75,000 psi
*7x30 Waters has a Winchester 1895 case head [ 30-30 parent] and couldhave gone to 70,000 psi.
*The 284 has a Winchester 1954 case head [284 parent], and possiblyshould not go more than 54,000 psi.
Hornady 7MM .284 DIA 162GR BIG GAME POLY CARB TIP 28452bullets and moly coated them
Comparing cartridge performance at close to optimum powder choice and 65kpsi:
7mmT/CU ........................26.1 gr H335 2330 fps -471 yards
7-30 Waters ........................30 gr W748 2456 fps -395 yards
7mmBR ...........................31.2 gr W748 2510 fps -360 yards
7mm IHMSA .......................40.2 gr Re17 2704 fps -247 yards
7mm-08 .......................40.6 gr IMR4895 2789 fps -198 yards
7mm-08AckleyImproved .........43.6 gr Re15 2833 fps -171 yards
7x57mm ...........................44.6 gr Re15 2843 fps -165 yards
7x57mmAckleyImproved .........46.4 gr Re15 2873 fps -150 yards
284Win .........................50.0 gr IMR4350 2890 fps -172 yards
280Rem ............................53.5 gr H414 2961 fps -152 yards
7mm Rem short action ultra mag 55.5 gr Re17 3015 fps -73 yards
280RemAckleyImproved ........57 gr IMR4350 3019 fps -71 yards
7mmRemMag ......................68.2 gr Re22 3129 fps -15 yards
7mmRem ultra mag ............83.3 gr IMR7828 3130 fps -15 yards
7mmWeathMag ....................71.8 gr Re22 3170 fps +7 yards
7mmSTW .............82.2 gr Ramshot Magnum 3158 fps 0 yards
*The 7mm IHMSA, 7mm-08, 7mm-08AckleyImproved, 7x57mm, 7x57mmAckleyImproved, 280Rem, and 280RemAckleyImproved have 1889Mauser case heads [7.65x53mm parent] with large Boxer primer pocketsand 65,000 psi is a reasonable max pressure for handloads.
*The 7mmBR 1889 Mauser case heads [7.65x53mm parent, 6mmBR parent]with small Boxer primer pockets and could have gone to 80,000 psi:
*The 7mmRemMag, 7mmWeathMag, and 7mmSTW have a 1912 H&H case head[375 H&H parent] and could have gone to 70,000 psi.
*The 7mmTCU has a 1950 Rem case head [.222 Parent] with small Boxerprimer and could have gone to 75,000 psi
*7x30 Waters has a Winchester 1895 case head [ 30-30 parent] and couldhave gone to 70,000 psi.
*The 284 has a Winchester 1954 case head [284 parent], and possiblyshould not go more than 54,000 psi.
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