325 gr. (.458 to .452) reloading experiment

[Siringo]

I have purchased a box of 325 gr. 45-70 bullets and will be trying them out to see what kind of accuracy and velocities I can get. How about we use this thread to track the progress of all of us that are going to try this?

I resized some of these today, using a Lee bullet Sizing die (.452). It took tremendous effort on my press to resize these. The were harder to do than the 400 gr. Speers. I would suspect that the jackets are thicker on the 325's. I even had to pound out a couple of them out of the die. I do use a lube -- Imperial Sizing wax. Make sure you remove all copper and lead from the inside of the die before you try re-sizing. Especially lead -- you can fuse the bullet to the die (like I did).

The length of the bearing surface of the 325 is about the same as the Speer 400 gr. The bullet length of the 325 is 1.115" versus the 250 gr. fxt is 0.995". MEANING that case capacity is reduced by 0.12" when using the heavy bullet. Note that the overal loaded cartridge length for both bullets is 2.25".

Since the case capacity is reduced using the heavy bullet, using slow powders like 1680 may not work. I do not have any of this -- so I am going to start out with the tried and true -- Lil'Gun. With the bullet seated, the case capacity for Lil'Gun is approximatly 34 grains. My goal is a minumum velocity of 1800 fps in a 16" barrel (duplicate a 45-70 load out of a 18.5 inch barrel). My starting load will be 28 grs, using wsr primers and I will work up from there. I am going to stop on the first go around at 32 grs.

Another powder to try would be V V 120.

For those of you that have "quick load" The bearing surface of the bullet is 0.5 inches. The case capacity of water with bullet seated is 35.8 grs of H2O. Set the max operating pressure at 40K.

[BD1]

A quick run through Quickload shows LilGun maxing out under the 325 grain FTX at 29.9 grains yielding 39,722 psi and 1773 fps.

BD

[Siringo]

Thanks -- what happens at 32.0 grs. of LG. Also -- what about V V 120?

Good information to have --

[BD1]

Quickload tells me that 32 grains of LilGun under the 325 grain FTX, sized to .452 yields 49,093 psi and 1938 fps. Keep in mind that while Quickload came pretty close to predicting the results of the 250 grain FTX, it way underestimated the results of LilGun under 300 grain cast lead boolits. It seems logical to assume that Quickloads data base for the .450 Bushmaster consists of a single factory loading of the 250 grain FTX at this point, as that's all that's been tested and put on the market. As to VV120, I don't think you could get enough in the case to get a good burn. VV110 seems more likely.

BD

[Siringo]

Could I ask for a favor? Run a 400 gr. Speer at 27.0 grs. Case capacity and bullet contact are are the same. The velocity that I came up with was 1500 fps.

[wildcatter]

I have purchased a box of 325 gr. 45-70 bullets and will be trying them out to see what kind of accuracy and velocities I can get. How about we use this thread to track the progress of all of us that are going to try this?

I resized some of these today, using a Lee bullet Sizing die (.452). It took tremendous effort on my press to resize these. The were harder to do than the 400 gr. Speers. I would suspect that the jackets are thicker on the 325's. I even had to pound out a couple of them out of the die. I do use a lube -- Imperial Sizing wax. Make sure you remove all copper and lead from the inside of the die before you try re-sizing. Especially lead -- you can fuse the bullet to the die (like I did).

The length of the bearing surface of the 325 is about the same as the Speer 400 gr. The bullet length of the 325 is 1.115" versus the 250 gr. fxt is 0.995". MEANING that case capacity is reduced by 0.12" when using the heavy bullet. Note that the overal loaded cartridge length for both bullets is 2.25".

Since the case capacity is reduced using the heavy bullet, using slow powders like 1680 may not work. I do not have any of this -- so I am going to start out with the tried and true -- Lil'Gun. With the bullet seated, the case capacity for Lil'Gun is approximatly 34 grains. My goal is a minumum velocity of 1800 fps in a 16" barrel (duplicate a 45-70 load out of a 18.5 inch barrel). My starting load will be 28 grs, using wsr primers and I will work up from there. I am going to stop on the first go around at 32 grs.

Another powder to try would be V V 120.

For those of you that have "quick load" The bearing surface of the bullet is 0.5 inches. The case capacity of water with bullet seated is 35.8 grs of H2O. Set the max operating pressure at 40K.

I think you are probably right about 1680, but if speeds increase with 296, after using lil gun, then a slower powder might be in the offing.

Imperial Sizing wax is the best of the best resizing lubes imo and after using it and then it still requires all the trouble you are going through to resize the bullets, we either need to go to a more, mechanically powerful resizer or we need to freshen the chambers, so we can use the case with standard 458 bullets, checking for thunk testing, and then let the bore do the resizing. Try polishing the sizer chamber with a moto-tool and start with some 320 grit.

And...my 18" 45-70 does factory ammo at about 1600fps. The various Factories advertise their ammo speeds at 1800fps using 405gr bullets, with a trap door "Rifle" Barrel, which is 32 5/8". Two things we have a much shorter barrel, as if you don't already know, and we can operate at much higher pressures/speeds. If we ring this 325 out, it has the potential, other than the Gas-Checked Hard-Cast LBT Style Lead bullets, has the potential as being our best "Standard Jacketed" A.K.A. Factory; heavy weight Dangerous Big-Game Bullet. And BD & BOOMER are all over the lead bullets.

[BD1]

.006 is a big squeeze on a jacketed bullet in one go. If you're gonna do a lot of this, you might get yourself a Lee .454 sizer and do it in two stages.
I do have about 8 lb of surplus WC 680 I'll try when I get a chance. I also ordered a couple of jugs of 297 from Pat. Unfortunately he's way behind, so it may be a couple of months before I get it.
BD

[Siringo]

Ouch! Here are my results of the day. I started at 28.0 grs of LG and went all the way up to 32 grs. BD -- the quick load seems to be pretty much on.

I did have marking on the base of the cases from the ejector and extractor from the beginning. I will try to post some pics. Essentially, the extractor shaved a little brass and slight wiping at the ejector. Strange thing is the marking are the same for 28 grs all the way to 32 grs. Also of some interest, every heavy bullet I have fired, no matter the charge, I get these markings. They do not appear with my 240 or 250 loading and also not with factory. Primer flatting was much the same as the factory rounds. Question -- can the heavy weights cause more rearward thrust than the lighter weights? Well, I guess according to Quick Load -- I took her to nearly 50K!

Maybe that LG is not the powder to use with the heavy weights. Here are the velocities. The charges of 29.0 to 29.3 and 31.3 to 31.6 all grouped within 1/2" respectively.

28.0 -- 1745
28.3 -- 1814
28.6 -- 1799
29.0 -- 1834
29.3 -- 1839
29.6 -- 1763
30.0 -- 1814
30.3 -- 1849
30.6 -- 1792
31.0 -- 1880
31.3 -- 1937
31.6 -- 1937
32.0 -- 1929

[wildcatter]

Ouch! Here are my results of the day. I started at 28.0 grs of LG and went all the way up to 32 grs. BD -- the quick load seems to be pretty much on.

I did have marking on the base of the cases from the ejector and extractor from the beginning. I will try to post some pics. Essentially, the extractor shaved a little brass and slight wiping at the ejector. Strange thing is the marking are the same for 28 grs all the way to 32 grs. Also of some interest, every heavy bullet I have fired, no matter the charge, I get these markings. They do not appear with my 240 or 250 loading and also not with factory. Primer flatting was much the same as the factory rounds. Question -- can the heavy weights cause more rearward thrust than the lighter weights? Well, I guess according to Quick Load -- I took her to nearly 50K!

Maybe that LG is not the powder to use with the heavy weights. Here are the velocities. The charges of 29.0 to 29.3 and 31.3 to 31.6 all grouped within 1/2" respectively.

28.0 -- 1745
28.3 -- 1814
28.6 -- 1799
29.0 -- 1834
29.3 -- 1839
29.6 -- 1763
30.0 -- 1814
30.3 -- 1849
30.6 -- 1792
31.0 -- 1880
31.3 -- 1937
31.6 -- 1937
32.0 -- 1929

QL seems to be right on this one..Holy Cow, approaching 2000fps with a 325,.458 bullet, and you might be in the low pressure area?

Again to totally assess your loads, from way down the street, can ya give us the before and after case head measurements, as big a sample as is practical is needed, but two rds, does give us peek, if incomplete. Did you get sooting down the side of the case, indicating a poor seal, which could be responsible for the marks (indeed, low pressures can cause increased bolt thrust)? If their was allot of sooting, with the pressures low, that could very well account for the marks. If you think this is the case, and you think that the pressures were indeed low, then more powder should stop the marks, the pressures will raise somewhat, but you may well be quite low now, so there could be room for an increase in powder, but we need the case head measurements to be sure. Try Pitted Bore's lighting/camera techniques, making pics very helpful.

Consider 296, sometime in the near future, to see if the marks go away.

[BD1]

Quickload tells me that 32 grains of LilGun under a 325 grain FTX sized to .452 should give 1877 fps @ 49,093 psi out of a 16" barrel, so the program is tracking away from this load as the powder charge increases. IMO the 31.3 grain load would be "the load" as it's giving you the same velocity and accuracy at nearly 5,000 less psi. Quickload tells me 31.3 grains of LilGun under this sized down 325 grainer should yield 1843 fps @ 45,750 psi in a 16" barrel.
It's also telling me that the powder charge is 100% combusted at 10" down the barrel.

I'm curious, what were you ES and SD values at the two nodes that gave you good accuracy? And, how far did the accuracy fall off in between those two loads?

BD