TRG-42 338 Lapua and IMR 4350?

[longrangehunter]

I need to break in the barrel of my TRG-42 and since I have an old tin can of IMR 4350 from 2003 with almost nothing in it I thought I'd get rid of it breaking in the barrel? Is there such a thing as breaking in a barrel that's chrome lined?

Seems way too fast for a 300 grain bullet yet Sierra shows it as their most accurate powder for the 300 SMK.

Anyone really have any luck using IMR 4350 in a big cased 338 and/or the Lapua Magnum?

 

[Charlie-NY]

IMR 4350 "may" be their most accurate powder for the big 300 grainer but it would be dog slow. If you're just breaking in the barrel why not use some cheap 250 grain bullets anyway? The 300 SMK's are a bit difficult to find lately.

For use other than breaking in a barrel I'd be looking at powder in the burn rate of RETUMBO.

 

[JD338]

IMR 4350 would be great for barrel break in.
Give Retumbo a try for the serious loads. It shoots very well in my 338 RUM.

JD338

 

[longrangehunter]

Slow is an after thought, but it did produce some nice groups right off the bat. I started w/ 73.0 grains..... oh gees, a whopping 2328 fps @ 20'; 76.0 2434; 78.0 2519; 78.5 2530 fps. The last shot something wasn't right, it wasn't an inch away from the others? The muzzle break screw went loose, and yes Thread Locker does need time to set up. Went w/77.9 grains @ 3.6800" COAL = 2.9250" CBTO. Big magazine box in the Sako BTW.

Ok, I had it shooting one hole groups if left to cool between shots, but 2507 fps@20' is a little slow, even w/ a 27 1/4" barrel. I did clean the barrel after the first five shots and spent a better part of a day cleaning the factory fouling shots out before I begun. All I can say is like most factory barrels they don't clean up well, but it is still new. I shot a total of twelve rounds, saved the last three to drive up the mountain and shoot at my target 1000 yards away. Only thing is the last time I shot it at 600 yards with the 300 Jarrett using a Berger 185 gr. Juggernaut bullet, it hit it so hard not only did it dent the Hardox, but it spun it around so hard it never went back in place! I thought it was facing the right way before I drove up there only to find out it wasn't moving even with the wind blowing.

Since I have 500 SMK's that's what I started using, and they usually will tell you if the gun will shot or not? But I also have a couple hundred 285 BTHP Match Hornady bullets and a few hundred of the 300 grain Lapua Scenar bullets. So in case you all are wondering why no Nosler bullets...... can't find any, local or other wise, and no I'm not about to pay for something and wait 4-6 weeks for them to ship me what I ordered in stock! NFW, besides I'm eager to get the new Long Range AccuBond bullets when they come out. Until then I'll work on my shooting with what I have on hand.

Here's something I thought of after todays shooting. I bought 4-5 lbs. each of RL 22, 25 and 33; H1000; and Supreme 780; plus what I had on hand of IMR 4350, 4831 7828, 7828 ssc, all the VihtaVuori 100 series powders, as well as almost every Hodgdon powder worth using! And the old stand by IMR 4350 works that well that I may never try something else unless this load doesn't shoot well further out? But I'll know before this weekend is over.

JD and Charlie....... what sucks is the four pounds of Retumbo I have is for my 6.5/300 WSM loads I developed, and I haven't seen any of that since last year! Besides, I have all those other powders to try before hand, and I here H1000 works real well in the Lapua. Wish I had bought all that US 869 last year when I saw it. Speaking of which, I liked it a lot better when I could walk into the LGS, buy something and try it out. If it worked, go back and still find the same lot powder of what I used! Those days were a lot easier on the wallet.

 

[Oldtrader3]

You can still find IMR 7828 SSC in gun shops. You might want to push your loads a little more and tune up at higher velocity with 7828 SSC?

 

[longrangehunter]

Well I looked at the data from my Shooter App, and if I push the same 300 SMK 125 fps faster (2650) it drops the elevation adjustment by 1 Mil at 1000 yards and adds 200 ft. lbs. more energy at that distance (1746.7 vs. 1546.2)

For me that doesn't amount to much since I just plug in the distance and shoot using the App. I have 28.4 mils of turret adjustment which will take me out to 1800 yards w/o using the mil dots in the scope with that bullet moving at 2525 fps. Which is way further then I'll ever be able to accurately make one shot hits at. The biggest factor is doping the wind which the extra speed could help a little, but then I have to deal with more recoil! The gun weights 14.5 lbs. w/ 5 rounds loaded in the magazine box w/out the bipod, that adds another pound. The muzzle break and the weight does reduce the felt recoil, but it's still stiff. Yesterday I shot 15 rounds off, but I'm not huge, I weight 170 when I'm fat with the extra ten pounds in my gut from winter. But I do have those other bullets that will be tested, which would include trying the slower powders I have on hand. I need to test the load further out this weekend and see if it holds under 1/2 MOA at six hundred yards. My 1000 yard setup is on the top of a mountain where the wind blows in every direction before it makes contact with the target. Nice thing is I can shoot the same piece of steel by just changing my location, although not perfect it works for not having to travel any real distance from my front door.

 

[FOTIS]

IMR 4350 would be great for barrel break in.
Give Retumbo a try for the serious loads. It shoots very well in my 338 RUM.

JD338

I concur!

 

[longrangehunter]

IMR 4350 would be great for barrel break in.
Give Retumbo a try for the serious loads. It shoots very well in my 338 RUM.

JD338

I concur!

I suppose I'll listen to the wisdom and break into my stash of Retumbo. I just hate using powder I have for another gun. Had this panic buying spree not set in I wont have to..... I could just go out and buy a new lot of it and see if it works? If I could just find it? My God, I have at least four pounds of everything else to try!

Thanks Guys, and have a great weekend, you both deserve it for the help you provide everyone here.

 

[longrangehunter]

So I cleaned the barrel of the Sako after the last ten rounds down the tube and it is cleaning up really nicely! Who would have thought, a chrome lined big bore that cleans up so fast with so few of rounds through it? Not me.

 

[longrangehunter]

I started a new thread on this question, but I thought I'd update what's going on with the load development.

So in the past I didn't like doing load development over another powder/bullet. I noticed some powders have a different Slickness to them in the barrel?

Anyway, I just put 5 rounds through the TRG-42 w/ the load I developed using 78.0 of IMR 4350. I ran out of the previous lot, and had to use a different lot # for the last two rounds then what I used for barrel break-in. Shot very well, one hole with the new lot of powder, but I'm tempted to see if I can achieve the same accuracy and increase the velocity at the same time using a different powder?

I now will need to use a different powder, RL 25, or 33, H1000, 780 Supreme, or N170, etc.

What is everyones opinion on shooting over a previous powder with a new powder using the same bullet during load development? I now have twenty rounds down the tube, it had been completely cleaned down to zero fouling before the last 5 rounds were fired.

Should I bother to clean the barrel prior to starting over with a new powder or just shoot over the fouled barrel?