PDA

View Full Version : Headspace for 162 Amax



chriscnf
12-12-2009, 04:08 AM
Hi guys...this is a real beginners question.

I'm trying to work up a load with the 162 Amax and ADI 2209 for my Stevens 7mm 08. The 2209 gives me good velocity but really doesn't fit. Rather than go to a faster powder such as 2208 (Varget) can I safely wind the barrel out to increase the headspace a couple of mm.

Cheers...Chris

rinodods
12-12-2009, 04:18 AM
Not sure how much good that will do you. As long as you are not failing the no-go then it should be safe. Sounds like more of a chamber issue really. If it were me I'd change out powder or bullet. No use working up a load you can't use. If you really want to use that combo you may need to look at getting the chamber cut a little differently so you can seat your load a little farther out. Sounds like you need a little longer throat.

GaCop
12-12-2009, 06:43 AM
I agree with rinodods, far safer to increase the free bore (like a Weatherby) than to lenghten headspace.

tammons
12-12-2009, 11:26 AM
Nope dont want to do that.

If you want to do some fire forming then do a 7mm-08AI or better yet have the barrel reamed to a straight 284.

Actually its such a long bullet most any proper powder will be a compressed load
to get good numbers out of it.

I ran a quickload powder comparison, fastest FPs per powder and 2209 in 10th down which is not too bad.

Somchem S365 - 104.5% 44.8gr 2.90" 2702fps
Ramshot Hunter
Hodgdon H4350
Winchester 760
Norma URP
Bofors RP19
Vihtavuori N550
IMR 4350
Accurate 4350
ADI AR 2209

43 gr of RL 15 should give you 2760 from a 24" barrel a very hot load.
That is off reloadersnest.

RL17 would show less pressure than RL15, but more compressed.
With a 7mm-08 shooting 162 amaxes over RL17 in a target barrel you should be able to get close to 2800 fps.

Not sure what it would get you with a 22" barrel vs a 26" barrel but probably 100 fps less.

I was getting 2640 with 40.5 gr H4895 at 2.9 col with a factory barrel.

chriscnf
12-12-2009, 04:51 PM
Thanks for the replies...I went and did some reading and understand what has been said.

47.5 gr of 2209 gives me 2770 fps. I suspect some of this is my suppressor.
42 grain of 2208 gives me 2690.

I actually fit the 2209 but have deformed the projectile a little in the seating process so I'm close to being viable. Using Winchester rather than Lapua helps a little and I can look at settling the powder better in the case.

I'm sure I'm being anal worrying about 70 fps. I've also yet to fully explore accuracy but initial results suggest 2208 might be best with the best 2 shot group under 1/2 moa while the best with 2209 is just over 1/2 (Savages rule).
(I use 2 shot groups because the Stevens consistently opens the group on the third shot...works for me)

I think I'm giving away a little accuracy going from 140 BT's to the 162 Amax but I think they should kill better at 600 yards.

All the best...Chris