243 SLR and H1000

[Bob3700]

Have been testing H1000 in my 243 SLR in an NRA prone/sling rifle. 7.5 twist Bartline 5R 30 inches long.

I have a good load with H4831sc but wanted to explore H1000 as many on this forum have spoken highly about its barrel life extending properties.

In this rifle I have tried the Berger 105 gr family of bullets as well as the 107 SMKs and 115 DTACS. In my barrels the DTACS have produced the smallest groups for me. I shoot them with the HBN coating.

One disadvantage of H1000 I found is that the kernel size of the powder is around .004 gr. It is harder to meter with any degree of accuracy. I turned to throwing light and then trickling up to the desired wt. . There is enough variation in the wt. of a single kernel of powder that getting your powder wts. within acceptable limits does take a bit longer.

A big plus is that the powder really does fill the case up and the loading density is approaching 100 percent.

I started on the low side with some of the charges that folks suggested on this forum. First shots over the chrono with the 115 DTACS were just over 2900 fps. I started upping the charge in .4 gr increments until I reached 3050fps. That load is certainly getting into the range of top pressures but nothing that indicated excessive PSI. Bolt lift was easy, no primer cratering, or extractor marks and the primers still had a rounded edge. I soft seat all my bullets .030" into the lands.

Over the chrono, 10 shots recorded an average velocity of 3050 with an SD of 5. Shot the loads at 600 yds with a sling and scope, it performed well (200-8X). As I do not shoot a scope all that well, my next test will be with my iron sights and will look to see the X count pick up. If it does that load will be a keeper.

So far so good.

Bob

 

[Raptor]

Bob what are you using for a load with the 115s? I am using it for the 107s and 105s. I find your statements to be true with what I have found also.

 

[Dgd6mm]

That is very good information Bob.

 

[Rtheurer]

Bob
I tried a couple new powders after Camp Perry also. On my list was H1000. I don't shoot the 115's anymore since the hybrid 105gr Berger came to life so all my data is with the 105 class bullets. I was pleasantly surprised with some really good groups in a 10 shot string at 600 yards. It was as good as my H4831SC load I usually shoot, plus another 70fps of velocity. ( right at 3100fps) Strain gage showed I was right in line with the H4831SC load which I have now loaded my brass 5 times without having to Full Length size. I mention that to bring to light Im not hot rodding anything and still getting good consistant & Accurate velocity/elevation. Im running my bullets at just under .0010 off the lands.
Looking at my notes. I shot 20 rounds off the bench at 600 yards and held 3.5" elevation. That's 20X's on the prone MR1 Target. 47.12gr of H1000, Winchester Brass, 105Hybrid, Tula Primer.

Ill be shooting this more to confirm. But when it holds for 20 rounds on the 600 yard target, that is a pretty darn good sign.
RussT

 

[Bob3700]

Russ and All,

I tried the 105 Hybrids and just could not get them to group as tight as the 115 DTACS.

My barrel has just under 2000 rds down the tube and has been set back once. So that may factor into my load.

Winchester brass
CCI BR2 primer
115DTAC Hbn coated
Seated .030" into the lands
Low neck tension for soft seating
H1000 - a bit over 48 grs.

The powder is right at the base of the neck.

I don't have a strain gauge but have been comparing the fired H1000 load primers against my 43.5 gr H4832sc load. Can't visually tell any difference.

One thing I will say is if you are using a custom action, often reading primers is difficult. The bolt faces are so clean and square, you have to look at the edges of the primers under magnification. Mine are still round at 3050 fps.

Bob

 

[Rtheurer]

Another advantage is that your running HBN. Im running Naked bullets until this barrel gives up and then I am going to give it a try.

I believe you could go up to the next node without any issues on the 115gr HBN bullets. Unfortunately your about at your max for capacity right now. Like you, I like a good 100% Load density or 102%. For what ever reason that I don't understand yet, Most of my good loads that STAY good loads are in that 98% to 102% case capacity.

I bet you will do just fine right where your at. Another 100fps is not going to win you any matches. You have most likely forgot more about shooting cleans at 600 and 1000 than I will ever know. Keep us posted on your H1000 adventures. Like I always say to folks. You can always go back to your old way right?

Shoot good Bob and thanks for sharing.
RussT

 

[rminut]

guys, do you think a .236 or .237 barrel would work better in this combo? I see these two barrels sold and wonder what application is best for either? I think I bought .237's. This SLR and the 6CM combo always get my attention, one of these days. thanks for any opinions on this.

 

[xdeano]

I went with a .237 barrel. I'd read a few things with guys shooting the heavies in the .236 barrels and it not working out as well, a little finicky i guess. I don't think it would matter a whole heck of a lot. Some one may chime in. I know Brux does a .236 and bartlein does a .237. both are good barrels. Flip a coin.

xdeano

 

[MOShooter]

Has anyone had luck with h1000 in a 24in barrel?

Scott

 

[LR coyote]

I tried it to day. 46.8 gr H1000 in my 25 inch Bartlett, 7.5 twist heavy.The H1000 at 100 yds was about half inch.The H4831SC was about .330 I went to 728 yds. The H4831 SC was 6 inches the H 1000 was 10 inches. The 4831 was 43.7 grains at 2930.The primer is flat but still round around the edge.My SLR will not go to 3000 with out pressure.The bullet is a 105 vld.

 

[LR coyote]

That is 25'' from the tip to the action.

 

[Heman]

You want to go .237. When I was setting up my .243 that was one of the things John told me the key to running it fast was the .237 as .236 will put to much strain on the bullet jackets.

H1000 is great stuff my .280 Rem, 7mmWSM, and 338LM loves the stuff.

 

[denobravo]

hey Bob
I about to rebarrel...243 AI or 243 SLR(isnt that a 6mm SLR) what are your thoughts

 

[XTR]

hey Bob
I about to rebarrel...243 AI or 243 SLR(isnt that a 6mm SLR) what are your thoughts

The 243 AI and the 6 SLR are pretty much the opposite ends of the spectrum for wildcats made off of the 243 case.

The upside of the he AI is it gives you the max case capacity you can get with the chambering, and an improved shoulder and it will give you the max MV that your able to achieve with the case. The whole point of P. O. Ackleys Improvements was to improve performance from the old highly tapered cases from 100 yrs ago. Look at the improvement made on the 30-40 Krag, it goes from about the capacity of the 308 to about the same as a 30-06. The 308 family if cases has very little taper, my personal opinion is that you don't gain enough to justify the fire forming hassle to do an AI on any 308 based cartridge, unless it is for a hunting rifle that will use 20 cases in it's lifetime.

The downside of the AI, Your cases have to to be fire formed, you still have the shortish neck of the parent case, you have souped up a case already known to be a barrel burner and if you are loading from a mag you haven't helped make room to seat long bullets and feed them, and the 40* AI shoulder has caused feeding problems for some folks.


6SLR does lose a bit of capacity from the parent, but not much. You can still run 105/107 class bullets around 3000fps with out stepping it it too hard. You make the cases with a sizing die in one step from new brass. For me it is no more work than any time I load new because I always at least run new brass over a mandrel. You get a 30* shoulder and a longer neck, IMO both of which make the 243 case better. Rumor has it gives better barely life.

I made a new 6mm this yr, and after looking at the options available, I went with the 6SLR.

 

[MattKubic]

The .236/.237 debate is a waste of time. I have both. I've put 1400+ down the .236 Bartlein at 3250fps. It is a 30" barrel. It has very minor cracking in the throat, but shoots amazingly well. Looks about like my last 6.5x284 after about 500 rounds. It is my #1 1,000yd prone gun. The same load is virtually identical in velocity to the .237 barrel of the same length. IMO, the biggest factor to take into consideration if you want to push 105s hard in a 6SLR or any big 6mm case is to stay away from tall lands. I believe the more shallow lands like the 5R in my Bartleins is easier on the jackets than taller lands in other bore profiles. I will agree with my boy RTheuer that accuracy trumps velocity everyday, all day. If I had to back down into the 3100-3150ish velocity range, it wouldn't hurt my feelings. My go to powder with the SLR is N160. I am about to chamber up another one in a 25"-26" barrel for some PRS type shooting and will try the H1000. My limited testing with it on the first barrel showed that 3050fps was close to max, but the numbers were very good.

 

[racesnake]

Has anyone tried IMR 7828 in the SLR?