Long Range Hunting Online Magazine

Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics


New build-chamber and barrel contour questions

LinkBack Thread Tools Display Modes
Unread 05-24-2012, 02:34 PM
Junior Member
Join Date: Apr 2010
Posts: 12
New build-chamber and barrel contour questions

I am planning my first long range build in 7mmRM on a trued early 80's 700 action. I am looking at 9-10 lbs or so final weight with a 26" Broughton or Krieger 1 in 9 twist barrel, utilizing 168 or 180 Berger VLD's or 162 AMAX. I have a couple of questions that I hope someone more experinced in doing these builds can answer:

Which chamber neck size:
.311 requiring neck turning
.315 could use factory ammo if clearance OK
.318 which I believe is the SAAMI standard

Which barrel contour?
I am thinking #5 or #6, preferring #6 (.750 muzzle diameter) although this might make it too heavy. Once built, I will work with it at ranges up to 800 yds but would go to a 1000 on deer sized game if the accuracy is there (and the shooter is capable!)

Your thoughts would be appreciated.
Reply With Quote

Unread 05-24-2012, 04:51 PM
Platinum Member
Join Date: Dec 2005
Posts: 2,483
Re: New build-chamber and barrel contour questions

Get a chamber made to SAAMI specs; no tight neck job. When the 7mm Rem. Mag. was popular for long range prone matches, folks shooting the best scores used that chamber or one a virtual copy thereof. When good, heavy, long match bullets were finally available, they shot sub 3/4 MOA at 1000 yards from both brand new cases as well as properly full length sized ones. The one I used decades ago tested a bit under 2.5 inches at 500 yards with new cases and a special select lot of Sierra Bullets' 168 HPMK's; the only range it was test fired at. When I shot it in a match, the wind was pretty wild. While it held good elevation at 1000 yards, its windage was not anything to write home about.
Reply With Quote
Unread 05-24-2012, 09:59 PM
Silver Member
Join Date: Mar 2011
Location: Cheney Wa
Posts: 168
Re: New build-chamber and barrel contour questions

We just finished up a new build in 7mm mag. It is wearing a shilen select match #5 sitting in a B&C Medalist with a blue printed older rem700 action, and wearing a Huskemaw 5x20 Blue diamond. the gun weighs 10.2 pounds. we had it out shooting a weekago at 1260 with no problem. If I were you and trying to keep the gun in the 9 to 10 pound range I would not go with the #6 contour, especially if you are gonna be packing it any distance.
Reply With Quote


Thread Tools
Display Modes

Similar Threads for: New build-chamber and barrel contour questions
Thread Thread Starter Forum Replies Last Post
Opinions on contour for new build (280 Rem) wamike Rifles, Bullets, Barrels & Ballistics 5 05-04-2012 10:03 AM
Switch barrel build update...new questions sanjuanfly Long Range Hunting & Shooting 13 03-13-2011 01:20 PM
WTB .308 3-4 contour barrel lazylabs Gun Parts - Stocks, Barrels, Actions, etc. 0 04-24-2010 02:35 PM
barrel life/ caliber questions to help with next build lovdasnow Rifles, Bullets, Barrels & Ballistics 19 06-14-2009 11:36 AM
Two questions, chamber cut and stocks tomtom Long Range Hunting & Shooting 1 02-04-2009 03:40 PM

All times are GMT -5. The time now is 07:50 AM.

All content ©2010-2015 Long Range Hunting, LLC