TRG-42 Bullet jump

[OD23]

Loading for the .338LM for the first time.......shot all that pretty factory stuff, and was pretty impressed. Have both 250gr and 300gr Scenars and SMK 300's on the way. Will be starting w/Retumbo and 7828SSC. Also will be using Federal Match mag primers. Curious what people have learned about bullet/lands clearance in the Sako's. How much jump? What COAL? I have a Stoney point OAL gauge and the bullet comparators. Was about to measure my chamber/throat and decided to ask the forum about their experiences. Also any load data or links to would be appreciated. I run .010" in my 5R and thought I might use that as a starting point. Any thoughts?

Thanks

 

[mavrick10_2000]

Re: TRG-42 Bullet jump

Unless you plan on single feeding your magazine and loading from it will let you know how long to load the bullets. The TRG's aren't overly long throated like a Remington factory barrel in the least.

If you load a little too long, the resistance to push those first few rounds out of the mag into the action will be stiffer. If you can't pickup the round because the bolt rides over the case head you're too long and need to seat shorter.

The Scenars and SMK's don't have much of a preference for seating. I haven't personally tested the Hornady 250's yet. My buddy shoots them and started to seat longer and now the bolt rides over the case head and won't pickup the round. Simple fix.

If you use a factory load to adjust your seater, your rounds will feed like butter. A simple visual to keep the best of both worlds is to seat to where the bullet tips are just short of the little ramp on the magazine follower. Make up 5 dummy rounds and test. You'll see and feel what I've described. Then adjust to your liking.

 

[ChrisGarrett]

Re: TRG-42 Bullet jump

I've always loaded to mag length for my TRG-42 1:12".

I think that I started out going 3.650", then found a bit of wiggle room to 3.730", so a little less than that for feeding's sake.

This being said, I got to test some of the new Berger hybrids and what I ended up playing with in my 2 day test session was strictly seating depth.

I loaded up 10 at 3.849"ish, which I figured out was about .020"-.025" off the lands of my tube with about 900 rounds down the pipe.

The Fins designed the rifle to shoot nuts on at 1000+ meters, feeding from a magazine, so don't worry too much about it.

Since I shoot only the 250s, I'll throw out H-4831sc, VV-165, H-1000 and VV-170.

Chris

 

[OD23]

Re: TRG-42 Bullet jump

Thanks guys. Headed to the loading bench momentarily.....rifle, magazine and OAL gauge in hand. Figure this thing out. Sounds like magazine function maybe the deciding factor in bullet seating depth. I really enjoy this rifle. Have only 90 rnds down the tube but was very impressed with it's accuracy using Lapua factory ammo. (300's & 250's). Any one with experience with the Sako or the .338LM that might have a tip or observation to share it is always appreciated.

 

[nick89rs]

Re: TRG-42 Bullet jump

Keep us updated OD23 I have a TRG42 sitting behind me waiting for its NEAR base to arrive so i can mount the scope. chomping at the bit here haha.

 

[Paladin2147]

Re: TRG-42 Bullet jump

If you are using the same bullet as factory and they have worked, use the same jump. I have - and accuracy is stellar in my TRG.

 

[LineofDeparture]

Re: TRG-42 Bullet jump

Here is what my TRG 10 twist likes.
300 Lapua Secnars
90.8 g retumbo
OAL 3.652
215m primers
2695 fps av
Sd 4.9
I shot 3/8 inch 5 shot groups with this load. It's defiantly my accuracy load.
Currently I'm working on the 300 berger otm's

 

[turbo54]

Re: TRG-42 Bullet jump

In mine, the 300smk shoots lights out loaded as long as they can be, yet still fit in the magazine with no binding/feeding issues.

 

[Agatha254]

Re: TRG-42 Bullet jump

The Scenars and SMK's don't have much of a preference for seating. I haven't personally tested the Hornady 250's yet. My buddy shoots them and started to seat longer and now the bolt rides over the case head and won't pickup the round. Simple fix.

 

[DUB DEE]

Re: TRG-42 Bullet jump

300's are to heavy and wont stabilize in the 1:12.

 

[turbo54]

Re: TRG-42 Bullet jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DUB DEE</div><div class="ubbcode-body">300's are to heavy and wont stabilize in the 1:12.
</div></div>

I use 300smk, from my 1:12 TRG, and they shoot great.

 

[ChrisGarrett]

Re: TRG-42 Bullet jump

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DUB DEE</div><div class="ubbcode-body">300's are to heavy and wont stabilize in the 1:12.
</div></div>

I use 300smk, from my 1:12 TRG, and they shoot great. </div></div>

You might be able to get the 300s to shoot better at altitude, but they are a bit long for a 1:12.

This being said, before I got my Sako, I bought 100 loaded rounds and some components from a fellow who gave away his AR30 to a friend in Irak.

300gr molied SMKs, over 94, 94.5grs of Retumbo, CCI 34s and new Lapua brass. I still have 80 of them left, as I shot a box early on.

At 100yds, it was about a 2" group, with no keyholing. Not great, but it could have been me at the time. I do recall them thumping my shoulder a bit more.

Unless you're trying to push a mile, I don't see the need for the more expensive, slower and more punishing 300s over the 250s.

Chris

 

[turbo54]

Re: TRG-42 Bullet jump

So far, I can say my 1:12 TRG WILL stabilize the 300smk at a density altitude as low as ~500 ft, with a muzzle velocity of between 2675 and 2725 fps.

 

[OD23]

Re: TRG-42 Bullet jump

Slow to get back, but I finaly got a few things done. The 300g Scenars contact the lands at a COAL of 3.725". Magazine function limits my length to 3.715" or 0.010" "jump". So that's my starting point. Loaded 20 rnds w/Retumbo in 4 charge weights, 90,90.5,91,91.5g. Will bust out the chrono asap and do a little load development. Might be this weekend......I'm a Heat and air guy and things are warming up here in Red Dirt country. BTW my rifle is a 1:10 version. Thanks for all the replies am very interested in keeping the conversation going, time permiting. nick89rs you will be very happy I believe w/your Near setup.....I really like mine. Still waiting on the SMK's. Will report range results when able. Thanks again to all!