Thread: "Extreme Velocity Spread"!

if it was me i would leave everything where it is and have a play with seating depth

Originally Posted by longrange308

if it was me i would leave everything where it is and have a play with seating depth

If I were to concentrate on bullet seating depth, what would you recommend? Example if I'm just touch now should I move to say .040" off the lands or what, what would you do?

I mean there's that many variables! There's powder types, bullets, bullet seating depth, neck tension etc, the variables are infinite! Indeed, Tracey Short once commented that, sometimes by the time he's managed to worked up a load that actually "shoots" in his rifle, he's worn out the barrel and it's time to buy a new one and start over!

I have had similar velocity spikes when seating projectiles to touch. I have since found that it is better to either jam them by 0.010" or jump them by at least 0.015". I suspect that a combination of the Hornady comparator (+- 0.003") and the usual variation in projectiles (+-0.002"), some of yours will be touching more than others. When seating it pays to measure each round and back off the seating die before seating the next projectile. Also as mentioned try 2217 or 2225. One thing I have found to reduce ES is to use a large rifle primer instead a magnum one, but this was in a couple of 7mmRM's. I used to use a heap of SST's but found quite a large dimension variation in them from box to box, and occasionally within on packet. So I stopped buying them.
The ES you are getting is probably a combination of several slight variations, but seating depth would likely have the biggest effect.

I forgot to add. I also found that SST's can like a large jump. Try seating a few to the canilure. You might be surprised. Good luck.

Originally Posted by Pnumatix

I have had similar velocity spikes when seating projectiles to touch. I have since found that it is better to either jam them by 0.010" or jump them by at least 0.015". I suspect that a combination of the Hornady comparator (+- 0.003") and the usual variation in projectiles (+-0.002"), some of yours will be touching more than others. When seating it pays to measure each round and back off the seating die before seating the next projectile. Also as mentioned try 2217 or 2225. One thing I have found to reduce ES is to use a large rifle primer instead a magnum one, but this was in a couple of 7mmRM's. I used to use a heap of SST's but found quite a large dimension variation in them from box to box, and occasionally within on packet. So I stopped buying them.
The ES you are getting is probably a combination of several slight variations, but seating depth would likely have the biggest effect.

I forgot to add. I also found that SST's can like a large jump. Try seating a few to the canilure. You might be surprised. Good luck.

Gee someone's up early!

Thanks for your input.

My bullet of choice is the 180gr Nosler Ballistic Tip as I've had great results with that over the years with knockdown power out of my .30-06, so because (at this stage) they all shoot around the same 1-1/2", my choice would be the Noslers. I can try a different powder, and seating depth but as I've said, there's so many combinations I'm gonna have to settle on something soon while I still have a barrel left. Poking the Chrony an extra meter or so off the barrel is the first place I'm gonna start with regards to velocity spread (just to see if it's a malfunction with the machine or not) however, that amount of ES is only peculiar to that one string!

Thanks.

Originally Posted by Pnumatix

I have had similar velocity spikes when seating projectiles to touch. I have since found that it is better to either jam them by 0.010" or jump them by at least 0.015". I suspect that a combination of the Hornady comparator (+- 0.003") and the usual variation in projectiles (+-0.002"), some of yours will be touching more than others. When seating it pays to measure each round and back off the seating die before seating the next projectile. Also as mentioned try 2217 or 2225. One thing I have found to reduce ES is to use a large rifle primer instead a magnum one, but this was in a couple of 7mmRM's. I used to use a heap of SST's but found quite a large dimension variation in them from box to box, and occasionally within on packet. So I stopped buying them.
The ES you are getting is probably a combination of several slight variations, but seating depth would likely have the biggest effect.

I forgot to add. I also found that SST's can like a large jump. Try seating a few to the canilure. You might be surprised. Good luck.

Actually, I'd thought a lot about your comments yesterday, and yours and my findings aren't too dissimilar!

I too have noticed a variation in bullets, even in the Nosler, when changing into a new box, and I have, in the past, backed my seating die off and advanced it with every bullet I seated to compensate for it, and thinking "this is so incredibly odd for one should be able to simply 'set and forget!'"... However, I've also found that you can wind the seater on that last .001" only to find that you get .0025" - .003" and you've over-shot your desired seating depth by one and a half to two thou!

Do you honestly think the Hornady bullet comparator is as much as +- .003" out? I found it to be pretty accurate myself (like, somewhere in the vicinity of .000" out!)

It actually makes sense that if you're operating that close to the lands that some may "Touch" closer than others, as odd as that may sound, so I do see where you're coming from, however, my main action I'll take, regarding velocity spread, is to move the 'Graph' further away from the muzzle next time!

Interestingly enough, the guy I know whose shooting SST's from his 6.5x55 Swedish, and getting 5 shots in well under an inch at 100m, surprised me when he said that he's got them seated about .040" off the lands! Also, I was reading a forum in the States whereby a guy was going on about seating them to the cannelure grove, and people were writing back in, speaking about the marvellous results they were achieving by doing so!

I have seated some .030" off the lands for my next trip to the range, so there's scope for me yet!

Thanks.

Originally Posted by Remington 5R .300 Win Mag

If I were to concentrate on bullet seating depth, what would you recommend? Example if I'm just touch now should I move to say .040" off the lands or what, what would you do?

I mean there's that many variables! There's powder types, bullets, bullet seating depth, neck tension etc, the variables are infinite! Indeed, Tracey Short once commented that, sometimes by the time he's managed to worked up a load that actually "shoots" in his rifle, he's worn out the barrel and it's time to buy a new one and start over!

if your touching now, move back 10tho ,then another 10tho etc
then try 3 shots without a chrony and see if it tightens up
es will shrink with consistancy in prep,
spent about 150 rounds in my 6.5 swede to try lower es ,came down to a lot of extra steps in brass prep
both my tikkas and my savage have liked about 20 tho from lands