jimbullet Posted October 25, 2015 Share Posted October 25, 2015 A quick question. I have been reloading 40S&W 180 gr TMJ projectiles. I have been using the same primers and powder brand ever since. I recently ran out of my previous batch and had to buy some more (win231) and noticed that with the same recipe (different batch meaning different batch number), using the same pistol, my hits are higher by 2-3inches from my previous load. Is this likely because of powder? Can different primers also cause change in point of impact? Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted October 25, 2015 Share Posted October 25, 2015 VERY unlikely the primer would account for a deviation like that. Pretty unlikely a different batch of the same powder would, either, though. Didja change the bullet? Sights change? Throwing little less/more powder? I would think any of these three items would be much more likely to cause that kind of change than a change of primers or powder lot. BTW, what distance are you shooting 2-3 inhes higher? Link to comment Share on other sites More sharing options...
rancher5 Posted October 25, 2015 Share Posted October 25, 2015 A quick question. I have been reloading 40S&W 180 gr TMJ projectiles. I have been using the same primers and powder brand ever since. I recently ran out of my previous batch and had to buy some more (win231) and noticed that with the same recipe (different batch meaning different batch number), using the same pistol, my hits are higher by 2-3inches from my previous load. Is this likely because of powder? Can different primers also cause change in point of impact? Absolutely, some powder changes faster than other,had HS6 older powder used almost .7 gr more to reach same PF as a new batch of HS-6,why always work up a load. Flip side did you bang your sights of out of adjustments Sent from my SM-G920V using Tapatalk Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted October 25, 2015 Share Posted October 25, 2015 my hits are higher by 2-3incheshad HS6 older powder used almost .7 gr more to reach same PF as a new batch of HS-6 Betcha 0.7 grains extra powder wouldn't raise the hits 2-3 inches. Link to comment Share on other sites More sharing options...
jimbullet Posted October 25, 2015 Author Share Posted October 25, 2015 Shooting at 25 meters. I tried to consistently keep my charge the same but in saying that it is likely there may have been an increase by 0.1 grains. Link to comment Share on other sites More sharing options...
Garmil Posted October 25, 2015 Share Posted October 25, 2015 Seems pretty excessive for a small change. I've used a different bullet different powders at a different power factor and had a closer poi than that. I'd guess something other than the powder/primer changed. Link to comment Share on other sites More sharing options...
jimbullet Posted October 25, 2015 Author Share Posted October 25, 2015 I kept a marker on the adjustment screw of my rear sight on its elevation screw and so I am sure that the sights did not move. I had two load batches. The first had 5.8grains on 180gr projectile and it produced a PF of 190, point of impact was 2-3 inches high. I scaled down to 5.6 grains with PF 180 but the point of impact appears to have not changed. My old load was a 5.5 grains at PF170 (border line) and that was bang on. If I zero at 15 meters, would it be a huge difference out at 25 meters? Link to comment Share on other sites More sharing options...
jimbullet Posted October 25, 2015 Author Share Posted October 25, 2015 (edited) Seems pretty excessive for a small change. I've used a different bullet different powders at a different power factor and had a closer poi than that. I'd guess something other than the powder/primer changed. I cant think of anything else that may have changed... New batch of projectiles but they are same brand and same 180gr. Primers same brand, different batch. Im open to ideas as to what would cause it. The pistol? STI Edge, Um, recoil springs changed from 12.5 lb to 13 lb. Edited October 25, 2015 by jimbullet Link to comment Share on other sites More sharing options...
rancher5 Posted October 26, 2015 Share Posted October 26, 2015 Seems pretty excessive for a small change. I've used a different bullet different powders at a different power factor and had a closer poi than that. I'd guess something other than the powder/primer changed. I cant think of anything else that may have changed... New batch of projectiles but they are same brand and same 180gr. Primers same brand, different batch.Im open to ideas as to what would cause it. The pistol? STI Edge, Um, recoil springs changed from 12.5 lb to 13 lb. Crimp,Powder,Brass,OAL,Sights,that itSent from my SM-G920V using Tapatalk Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted October 26, 2015 Share Posted October 26, 2015 The first had 5.8grains and it produced a PF of 190, point of impact was 2-3 inches high. I scaled down to 5.6 grains with PF 180 but the point of impact appears to have not changed. My old load was a 5.5 grains at PF170 (border line) and that was bang on. Jim, I'm confused ... (but, I am almost 71 years old). Dropping from 5.8 to 5.6 grains didn't appear to change the POI ... I believe that's pretty much what everyone is saying - that small a difference should not affect POI too much. So, I'm not sure why you think that a change of powder lots, or a 0.7 grain difference would make a significant change in POI? I would guess that if 5.5 gr is dead on, that 5.8 might hit couple inches higher, but not a different lot of the same powder. BTW, usually sighting in iron sights (or even a dot, for that matter) at 17 or 25 yards, should be pretty much the same. I wonder how large a group (sample size) you've been shooting at 25 meters - if I shoot five, five-shot groups, they'll wander by a few inches at 25 meters. I now shoot 15-20 shot groups, drop the flyers, and measure the remaining tight group. Firing five shots at 25 meters just might go up or down by 2" with no apparent reason other than inherent accuracy of the gun, and ME. Link to comment Share on other sites More sharing options...
jimbullet Posted October 26, 2015 Author Share Posted October 26, 2015 Thanks Hi Power Jack, The reason I was thinking maybe it's the change in powder batch is because I have been using the same type of powder with my old stock for the last 2years. I had a load at 5.5gr that gave me a dead center hit zeroed at about 20 meters. I bought a new batch as used up my stock powder, increased at first to 5.8 and now settled to 5.6 and in both instances when shooting at 25 meters, POI appears to have been 2inches higher. I've done about 40 rounds to test the 5.6 load. I have done no other changes to my press except powder charge and that was what made me think could it be the powder but it appears there should not be too much of a change in POI. I might just try to have another go at the range and see. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted October 26, 2015 Share Posted October 26, 2015 BTW, how large are your 10-shot groups at 25 meters with that particular gun (what gun is it?) and that particular load? Link to comment Share on other sites More sharing options...
jimbullet Posted October 26, 2015 Author Share Posted October 26, 2015 It's an STI edge, groupings are about 2 inches - putting aside any flyers due to operator error which would expand it to about 3 1/2 inches. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
bowenbuilt Posted October 28, 2015 Share Posted October 28, 2015 Changing out a well used recoil spring for a new one, even at a lower value can sometimes cause an impact change. You might switch back and try it. Link to comment Share on other sites More sharing options...
jimbullet Posted November 7, 2015 Author Share Posted November 7, 2015 Range report: I've just made a couple of elevation downward change, shifted to my old recoil spring and sighted in properly to 20 meters, and it appears that the sights are bang on once again....dead center. thanks for all your responses. I cant really pinpoint what it was but I suspect 90% was human error perhaps not properly gripping the gun and 10% perhaps the combination of everything else from sights, recoil spring or even that minor change in powder and the mix brass I have. Happy though that its now bang on and I can once again concentrate on shooting with confidence. Link to comment Share on other sites More sharing options...
Garmil Posted November 7, 2015 Share Posted November 7, 2015 Glad to hear you got it figured out Link to comment Share on other sites More sharing options...
wgj3 Posted November 7, 2015 Share Posted November 7, 2015 Different/new recoil spring could definitely have an impact...I would think... *feel free to correct me if I'm wrong. Link to comment Share on other sites More sharing options...
jimbullet Posted November 7, 2015 Author Share Posted November 7, 2015 I took that advise too saying to myself it wouldn't hurt. So I put it back as dont have time to mock around since I am preparing for a match in two weeks time. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
LilBunniFuFu Posted November 7, 2015 Share Posted November 7, 2015 Most likely it was the recoil spring changing the unlocking timing. Link to comment Share on other sites More sharing options...
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