6.5X47 Lap imp Quick Load help.

[RockyMtnMT]

In a different thread I posted results out of a rifle in this chambering. I was summarily told that I was lucky to be alive and too stupid to own a rifle let alone load and shoot one. ( Not in so many words, but more or less. ) My response to this was not the best, and for that I apologize. Those who called me out as a liar or too stupid to know what I was talking about were unable to actually explain why. Not even able to respond to a PM.

So I am starting a new thread to find out where I could have gone wrong to get the results that I have. I do not come here to get called an idiot, I come here for quality information, and hope that I can also contribute some.

Here is the load and results.

140g Berger
Reloader 15 40g
2.890 col
CCI BR2 primer
2964 fps average

This is shot @ 3000 ft elevation. I did not record temp, but probably about 50 to 60 deg f.

I ran it through two Shooting Chrony's back to front at 15'.

The rifle is a Stevens action, that has been squared, on a 22" 1.25" no taper bull barrel. The barrel has been treated with Gun Juice.

Later today I can get case capacity in grains of water if needed.

Steve

 

[Kevin Thomas]

Steve,

I don't have the dimensions for the 6.5x47 AI, but I did run the load using a standard 6.5x47 cartridge. It showed about 73K PSI, but the extra capacity of the AI version would of course drop this. Water capacity would help, if you can determine that, I'd be happy to take another look.

Velocity with a 22" showed about 2850, but there's a lot of variables here, fast barrels and slower ones, so I wouldn't put too much stock in this without knowing I had the accurate inputs. Not to pick at a sore subject, but what brought you to this load? Did you get it from somebody, or work up to it yourself? One thing I'll caution you about, is the fact that very straight-walled cases (those with the body taper mostly removed) can be a bit more difficult to read pressure signs from. The typically sticky bolt lift that you see with most cases in high pressure loads simply don't materialize in this case design. I've dealt with several of the Gibbs cartridges, and there's almost no way you can get sticky bolt lift with any of them. The pressures there, but you don't see that particualar indicator, and you need to rely on others. Prefereably, the sum of several other indicators, to include velocity, case longevity, case head expansion, etc..

hope that helps.

 

[RockyMtnMT]

Steve,

I don't have the dimensions for the 6.5x47 AI, but I did run the load using a standard 6.5x47 cartridge. It showed about 73K PSI, but the extra capacity of the AI version would of course drop this. Water capacity would help, if you can determine that, I'd be happy to take another look.

Velocity with a 22" showed about 2850, but there's a lot of variables here, fast barrels and slower ones, so I wouldn't put too much stock in this without knowing I had the accurate inputs. Not to pick at a sore subject, but what brought you to this load? Did you get it from somebody, or work up to it yourself? One thing I'll caution you about, is the fact that very straight-walled cases (those with the body taper mostly removed) can be a bit more difficult to read pressure signs from. The typically sticky bolt lift that you see with most cases in high pressure loads simply don't materialize in this case design. I've dealt with several of the Gibbs cartridges, and there's almost no way you can get sticky bolt lift with any of them. The pressures there, but you don't see that particualar indicator, and you need to rely on others. Prefereably, the sum of several other indicators, to include velocity, case longevity, case head expansion, etc..

hope that helps.

Thank you Kevin,

This load was worked up to. Actually went above and came back down. Determined this load by watching for normal pressure signs on brass, primer, and muzzle vel. What pressure is too high for this case?

I'll have the h20 capacity later today.

Steve

 

[Kevin Thomas]

That may be part of the problem; several of those signs lie. Primer appearance is one of the most commonly referred to pressure signs, and they will tell you a thing or two about pressures. They'll also lie to you like a politician in an election year. I've seen far too many fired primers that most would look at an immediately declare the load to have been far, far too hot, when they were actually quite mild. Headspace issues can cause that. I've also seen primers that looked like the load was rather mild, when in fact it was **** near proof load levels. Like I said, they lie. Bolt lift is another that becomes unreliable when dealing with cases with minimal body taper. As I mentioned, stick a case in a Gibbs and you've already gone well beyond proof load pressures.

Normal absolute max for the 6.5x47 is (I believe) about 62K, normal loadings probably running an average of around 55K PSI, but I'd have to verify that to be sure. In most cases, I'd want to maintain the same pressure range as the original parent case. The advantage lies in the added capacity of an Improved case, and not by running higher pressures.

In the case of the 6.5x47, I wouldn't expect too much of an improvement in velocity, simply because the case isn't really "improved" that much. It has a reasonably sharp shoulder and not too much body taper. In short, there's not much to blow out when you fireform. Cases like the 22-250 or 257 Roberts show a very pronounced increase, due to their extreme (by modern standards) body taper and relatively mild shoulder angles. Not knocking your choice here, just saying, not all cases benefit equally by the Ackley treatment. P.O. knew this, and said as much about several cartridges.

 

[BountyHunter]

Good info posted.

I would go to www.6mmbr.com and they have a specific reloading thread/forum with lots of info for the standard 6.5x47 which you can easily work from.

lot of 6.5 shooters there.

BH

 

[RockyMtnMT]

That may be part of the problem; several of those signs lie. Primer appearance is one of the most commonly referred to pressure signs, and they will tell you a thing or two about pressures. They'll also lie to you like a politician in an election year. I've seen far too many fired primers that most would look at an immediately declare the load to have been far, far too hot, when they were actually quite mild. Headspace issues can cause that. I've also seen primers that looked like the load was rather mild, when in fact it was **** near proof load levels. Like I said, they lie. Bolt lift is another that becomes unreliable when dealing with cases with minimal body taper. As I mentioned, stick a case in a Gibbs and you've already gone well beyond proof load pressures.

Normal absolute max for the 6.5x47 is (I believe) about 62K, normal loadings probably running an average of around 55K PSI, but I'd have to verify that to be sure. In most cases, I'd want to maintain the same pressure range as the original parent case. The advantage lies in the added capacity of an Improved case, and not by running higher pressures.

In the case of the 6.5x47, I wouldn't expect too much of an improvement in velocity, simply because the case isn't really "improved" that much. It has a reasonably sharp shoulder and not too much body taper. In short, there's not much to blow out when you fireform. Cases like the 22-250 or 257 Roberts show a very pronounced increase, due to their extreme (by modern standards) body taper and relatively mild shoulder angles. Not knocking your choice here, just saying, not all cases benefit equally by the Ackley treatment. P.O. knew this, and said as much about several cartridges.

I agree on the imp. We were looking at the 6 Dasher when we decided to improve the parent case. We own the reamer so future chamberings will be the same.

If I remember correctly we were trying to stay around 65,000 psi after reaserch before load development.


Steve

 

[w123driver]

Can't comment on improved 6.5x47L, but I have 6.5x47L on Stevens 200 nutless built, sporter contour McGowen barrel 20" (1 in 8.5 ROT). i am getting 3000 +/- 50 fps with 39 gr RL15 and 120 gr Hornady Amax combo. I just used the same load as my gunsmith friend uses form the rifle he built with the same reamer. As a matter of fact, just finished walnut stock for it, to finally replace tupperware.

 

[RockyMtnMT]

That is a beautiful piece of wood.

Steve

 

[Mikecr]

Steve, I might be the poster implying that you were lying..
This was not my intention, but instead to flag a dangerously erroneous load posted for all readers. My direct implication is that I do not believe your numbers. That you are mistaken. I've been too busy to assemble a postible QL shot for you. I'll try here.

I drew a 6.5x47L improved with a 35deg shoulder via moving shoulder up(to provide higher capacity from the case) in 'Cartridge Designer'. This indicated ~51grH20 capacity.
Then I run your numbers in QL with a similar case set at 51grH20. I assumed bullets touching lands to get highest velocity from the load, and seated a 140gr BT bullet for your COAL.
I get ~2850, at very high pressures. I could calibrate any notion but pressures would continue to climb before a match to your results could be reached.
I'm aware that overpressure loads are the latest trend to smaller grouping. But this is not beneficial to hunting, and would serve only to overun the reloading board with oversizing problems(like it isn't already)..

 

[RockyMtnMT]

Steve, I might be the poster implying that you were lying..
This was not my intention, but instead to flag a dangerously erroneous load posted for all readers. My direct implication is that I do not believe your numbers. That you are mistaken. I've been too busy to assemble a postible QL shot for you. I'll try here.

I drew a 6.5x47L improved with a 35deg shoulder via moving shoulder up(to provide higher capacity from the case) in 'Cartridge Designer'. This indicated ~51grH20 capacity.
Then I run your numbers in QL with a similar case set at 51grH20. I assumed bullets touching lands to get highest velocity from the load, and seated a 140gr BT bullet for your COAL.
I get ~2850, at very high pressures. I could calibrate any notion but pressures would continue to climb before a match to your results could be reached.
I'm aware that overpressure loads are the latest trend to smaller grouping. But this is not beneficial to hunting, and would serve only to overun the reloading board with oversizing problems(like it isn't already)..

Fair enough. My weight measurement for water came to 49.5g. My intention was never to lead any one to a dangerous load. Again the only other variable is the Gun Juice treatment. Past treatments have shown from 25fps gain to 100fps gain. This particular barrel was never shot with out GJ. So I do not know what kind of gain it produced. We have since treated every new barrel with the product prior to break in. What pressure did QL show at 2850fps?

As stated before by Kevin, not seeing any pressure signs does not mean that we are not overpressure.

So, this brings me to my next question. With these wildcat cartridges, how does one know when you have reached pressure?

Thanks,

Steve

PS. It has a 40 deg shoulder.