30 br

30br at 550yds

Our club had an informal sniper shoot at 550yds that I had some success using 135 smks over 31.7 Re7, Krieger lv 17 twist barrel on trued Rem700.
Same load with H4198 also was very good. Load vel. at 2824.

Rich
 
135 gr. SMK 30BR Loads

richie301 said:
Our club had an informal sniper shoot at 550yds that I had some success using 135 smks over 31.7 Re7, Krieger lv 17 twist barrel on trued Rem700. Same load with H4198 also was very good. Load vel. at 2824.

I'm about to load up some of these (135gr. SMK) in a std. 30BR 17T. I called Sierra for load info and noticed your H4198 load (31.7gr.?) is over their max. of 31.5 gr. Were you getting high pressure indications?


Is anyone else using the 135gr. SMK's in a 17T std. 30BR? If so, what other powder/loads are working? I have H4198, N130, N133, and H4895 on hand. Anyone getting round holes at 100yds. and keyholes at 600 yds.? Do these bullets have to be loaded at/above recommended max. in a 30BR to prevent tumbling at 600 yds.? Any info would be appreciated.
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135 smk

I had no pressure signs, but we all know to start low and work your way up. My 30brs (both 17's @ 24") are sensitive to 1/10th grain increments. The load you describe about keyholes at 600yds probably means the velocity has dropped below the stability threshold. Bullet length is 1.071 and according to berger updated calculator it is marginally stable at 2824 fps 500 elev. 60 degree day.
 
No Success Yet

Thanks for your response. Doesn't seem like there is a lot of interest in or experimenting with these bullets in 17T 30BR rifles for distance shooting, but here's my (lack of) progress so far.

The first range trip with preloaded rounds was unsuccessful. Loads started at 30.6 and went to 31.7 (H4198). The 135 SMK's were moly coated. Bullets were seated well into the lands, with all rounds loaded to the same length, varying powder charge only. Five shot groups at 100 yards were uniformly the worst ever from this rifle. All holes were round, with no evidence of tumbling at 100 yards. Hard CCI400 primers showed no pressure signs at the top 31.7 grain load.

I am hoping that velocity simply did not get high enough to properly stabilize these bullets and this was responsible for the poor groups and flyers. I plan to work up from 31.7 in .2 grain increments to see if things tighten up before pressure signs are encountered. I will also seat the bullets a little deeper to perhaps just touch the lands. If this is unsuccessful, I'm thinking of trying a slower powder.

Any thoughts or experiences with this bullet in 17T 30BR chamberings would be appreciated. It would be nice to get these bullets shooting reasonably tight groups at 100 yards and therefore being able to realize the advantage of the higher BC at 600+ yards.
 
KC57 said:
Thanks for your response. Doesn't seem like there is a lot of interest in or experimenting with these bullets in 17T 30BR rifles for distance shooting, but here's my (lack of) progress so far.

The first range trip with preloaded rounds was unsuccessful. Loads started at 30.6 and went to 31.7 (H4198). The 135 SMK's were moly coated. Bullets were seated well into the lands, with all rounds loaded to the same length, varying powder charge only. Five shot groups at 100 yards were uniformly the worst ever from this rifle. All holes were round, with no evidence of tumbling at 100 yards. Hard CCI400 primers showed no pressure signs at the top 31.7 grain load.

I am hoping that velocity simply did not get high enough to properly stabilize these bullets and this was responsible for the poor groups and flyers. I plan to work up from 31.7 in .2 grain increments to see if things tighten up before pressure signs are encountered. I will also seat the bullets a little deeper to perhaps just touch the lands. If this is unsuccessful, I'm thinking of trying a slower powder.

Any thoughts or experiences with this bullet in 17T 30BR chamberings would be appreciated. It would be nice to get these bullets shooting reasonably tight groups at 100 yards and therefore being able to realize the advantage of the higher BC at 600+ yards.
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I have never shot 135's out of a 30br. I have shot 125's and I used the same load I would have for 115's. About 34.5 grains of 4198. I wouldn't start that high with the 135's but I think you have room to go higher. I would also start with the bullets off the lands or just barely touching.
 
Wrong twist rate

I have shot both 125 & 135's sms .30 BR, but not in a 17 twist barrel. I used a 15 twist and the accuracy was great at 2 &300 yes, I also used a powder that did not create a pressure problem, 8208XBR. When I get a chance today I will dig out my load data book and tell you what the loads were in case your interested.
 
I have shot my standard 30BR load at 400 yard Claybreak Matches. 112 grn out of a 1-18 twist. I think it gives about the same performance as a 6PPC with typical 68 grn match bullets.

Why not try that out of the 1-17. That 125/135 doesn't give you enough of a BC advantage over a 112 to make up for the accuracy potential of the 112.
 
jackie schmidt said:
I have shot my standard 30BR load at 400 yard Claybreak Matches. 112 grn out of a 1-18 twist. I think it gives about the same performance as a 6PPC with typical 68 grn match bullets.

Why not try that out of the 1-17. That 125/135 doesn't give you enough of a BC advantage over a 112 to make up for the accuracy potential of the 112.
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Perhaps. Or perhaps not.
Published BC's of .30 (BIB-112) vs. .370+ (135 SMK@2900fps).
The rifle shoots 112 BIB's very well at 100 and 400 yards. (Although at present my 6BR (105gr VLD's) shoots better at 400+ yards.) And I'm working up 112 X-OUTS as well. I'd like to see if a windy day advantage can be obtained with the 135's at 600 yards. But they will have to demonstrate close-to 112 gr. precision at 100 yds. first. And you may be right, it might not happen.

But sometimes I like to try different things.
 
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