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NormaMag
07-09-2014, 01:46 AM
Hello

I`m planning building a 300 Norma imp for long range shooting and 1000 yard bench rest.
What is the best shoulder angle for best precision? Don't know if I should go for, 30,32.5, 35, 37.5 or 40 deg.
I know Tom Sarvers 300 Hulk is 33 deg shoulder and extreme accurate.

Lee Martin
07-09-2014, 09:04 AM
I think you're hard pressed to say one angle between 30 and 40 is the best (and I'd suggest there isn't any difference within that range). If a lot of guys in 1,000 are shooting the Norma Improved, I go with the most common angle. It'll allow you to share data.

-Lee
www.singleactions.com

alinwa
07-09-2014, 08:05 PM
33-35 degrees, no more, no less IMO

It's not about "precision" it's about maintenance. 40* Ackley's SUUCKKK! in this regard

al

Lee Martin
07-09-2014, 10:37 PM
Al....I'm curious. What specifically happens to case life or maintenance when you move to 40 degrees?

-Lee
www.singleactions.com

alinwa
07-10-2014, 02:39 AM
IME with a case as large as the Norma, or more specifically with a shoulder as long as the Norma case (neck diameter VS shoulder diameter) the 40* shoulders will bounce on resizing. You end up shoving the shoulder/body junction back too far while trying to gain clearance at the neck/shoulder junction

I have found 35* shoulders to offer good resistance against sliding while not exhibiting the bouncing problem. I've found bounce cases like 22-250AI, .243AI etc.

On the other hand I've had no problem with the 30-06AI in 40* because the shoulder is short enough to offer good support.

opinionsby






al

NormaMag
07-10-2014, 09:33 AM
On the other hand I've had no problem with the 30-06AI in 40* because the shoulder is short enough to offer good support.

opinionsby

Interesting. I have both 6.5x55 AI and 30-06 AI without any problems. I also just ordered a 300 Blaser imp with 37.5 degree shoulder reamer.It`s basically a 300 Dakota with a bit longer neck and 37.5* shoulder. Hope I wount get problems resizing that as I will use it in long range BR competitions :/

alinwa
07-10-2014, 11:30 PM
Interesting. I have both 6.5x55 AI and 30-06 AI without any problems. /

Have you ever reloaded cases 30-50-100 times?

NormaMag
07-11-2014, 06:32 AM
Have you ever reloaded cases 30-50-100 times?

No newer. Only around 20. What do you think about the 37.5 degree Blaser? Problem with sizing?

Dave Tooley
07-11-2014, 07:59 AM
No newer. Only around 20. What do you think about the 37.5 degree Blaser? Problem with sizing?

I settled on 30 as max for the shoulder angle. It's what I used on the Yogi and BooBoo series of rounds after many years chambering and shooting Ack Imp rounds. Never had any complaints and brass lasted indefinitely. After 30 what is there to gain?

vinny
07-11-2014, 08:49 AM
308 Baer Cub, it's a proven winner at Williamsport. Call Bruce Baer for deets.
7173494077

NormaMag
07-11-2014, 08:54 AM
I settled on 30 as max for the shoulder angle. It's what I used on the Yogi and BooBoo series of rounds after many years chambering and shooting Ack Imp rounds. Never had any complaints and brass lasted indefinitely. After 30 what is there to gain?

Not much I guess Dave.
My die set is already finished, and reamer is ordered, so its too late changing it now :/
Hope 37.5 will work ok with pretty good brass life.If not, I need to find another solution.

NormaMag
07-11-2014, 09:03 AM
What about the 6 Dasher. Bad brass life?

Lee Martin
07-11-2014, 09:57 AM
A friend of mine shoots a 6mm Dasher and is well beyond 30 reloads on Lapua hulls.

-Lee
www.singleactions.com