Three PP'ed Bullets
A Tale of Three PP'ed Bullets
Friday, February 1, 2008 turned out to be a fine day for load-testing from the 1,000-yd line at the Sacramento Valley Shooting Center. The weather has been wet and windy for most of the past 2 weeks. Our long-range practice didn't look viable the middle of the week, but a hardy bunch of intrepid (http://www.thefreedictionary.com/intrepid) BPCR Creedmoor marksmen showed-up in the AM anyway. The fog didn't lift until round-about 9 AM so we milled-about "talking story" and checking out PP'ed ammo that some of us brought to test-fire. Mike Calvo kindly provided a warm 5-wheel, La Casa Pequeña, for all attendant to hang-out in while the fog and chill lifted. Seven, old, smelly, fat-cats in a small travel-trailer reminded me of my 7th grade PE locker room, PU!
Both Arnie Moos and I focused on testing PP'ed bullets during the testing session. Luckily the wind was reasonably consistent and not too strong. It was a bit tricky on our first testing relay of about 45 minutes. Each of the relays did two testing sessions. We also saw some interesting test results from Tark's Browning 45-70 and "His Honor da Mayor's" (Gerry Podesta's) recently purchased 45-100 Ball-wall from George Liotta. Both rifles sport 18-twist Badger barrels, more about them later.
Arnie and I both shot together during the first testing session on the same target, pair-firing, so we were talking about how our loads were doing during the entire session. For the second testing session we each had our own target.
Arnie was shooting a Shiloh Sharps with a hand-lapped, 18-twist Badger barrel. I spent about 4 hours working to put a choke in the barrel, before it was fit-up to the action, that is probably in the range of 1/3 thousandths taper over the last 6" of the barrel. Steve Rhoades did the honors of fitting-up the barrel for Arnie. Arnie's rifle is a real shooter using both PP and GG bullets. This chamber design might be a reasonably compromise if one wants to shoot PP and GG bullets. Arnie has an excellent load launching the Paul Jones "Money" bullet with 90-grains of Swiss 1.5. It is chambered in 45-90, match reamer by DanTDesigns and fabricated by Dave Manson of Manson reamers. Here's a diagram of the reamer.
Arnie used this rifle to win our last Creedmoor match, shooting the Paul Jones "Money Bullet" on Saturday and a "Money PP Bullet" on Sunday. His "Money PP Bullet" has a diameter of 0.450", patched to 0.4580". The rifle has been put to "the test" and shown to be a winner. This past Friday he was testing the Buffalo Arms 0.4420" diameter PP bullet wrapped with 2.3 thousandths BA 100% cotton paper. It was wet-wrapped, dried and dip-lubed. His load components were:
45-90 Starline brass
Arnie reported that the load didn't shoot very well at first, but after a number of rounds it started to group and shows some promise. We collected paper from in front of the muzzle for both of our various loads. Since Arnie was using BA paper and I wasn't it was easy to tell whose paper was whose. Arnie's paper was in large chunks with NO cutting through the paper. There is a picture below that shows both of our patch paper collected from the ground in front of our muzzles. It is my current thinking, about how to design and load for PP to produce match-grade accuracy and NO flyers, that the following should be done:
Barrel should be choked
Arnie is ordering a Brooks 1.50" long ULRB PP version for his 18-twist Sharps. It should be just the ticket cast in either 16-1 or 20-1 alloy. Bullet weight should be about 550 grains.
Your's truly was shooting an 18-twist 45-90 Sharps chambered with a replica of the original Sharps PP match chamber copied from an original Borchardt. Two bullets were tested and one of the bullets was cast in two different alloys: 16-1 and 20-1, to see if any accuracy difference could be ascertained. None was. Also, two paper thickness were tested: 1.4 and 1.6 thousandths thick. All of the test bullets had their paper-jackets dip-lubed. Below is a picture the 3 bullets talked about in this article, two of which were shot during this testing session:
The far left is the original length (1.500") Sharps LR bullet, 572 grains. Next is the shortened version (1.450"), 549 grains and finally, the 1.550" long ULRB, 572 grains.
One of the interesting results from our testing session showed that the bullet design concepts I've been working on hold water. The rifle shot on Friday was used last year at Raton during the Long-range BPCR Target Rifle Championships. The load was very accurate, but the 1.50" long Sharps LR bullet was too unstable to produce high performance from the 1,000-yd line. It produced holes from that yard-line that were markedly elliptical, about 1.25 times as wide as high or about 6 to 7 degrees of bullet yaw. That is way, way too much instability if there is the least bit of challenging wind. The bullet was cast in 20-1, weighed 572 grains and launched with 90 grains of Swiss Fg. The 1.55" long Brooks Ultra Long-range Bullet (ULRB) was also launched with the same 90 grain powder charge during this testing session to see what the holes would look like when fired from the 1,000-yd line. His Honor the Mayor had my camera down in the butts to take some pictures of the holes. The current working hypothesis is that nose design makes a critical difference in bullet stability required for top match performance in LR matches. I was not disappointed. Even though the ULRB is 50 thousandths of an inch longer than the Sharps LR bullet, both weight the same, 572 grains, the ULRB produced much rounder holes. They are not what I have come to demand for a top performing load from the 1K-line, but they are much, much rounder than the Sharps LR bullet. Here is a picture for your review.
If you look closely at the hole, the 7 o'clock area has been hit by the base-edge. It was out of alignment with the nose. If the cardboard had been pushed back into its original position you would see where the point of the bullet was not centered-up in the elliptical hole. The nose went though at about the 1 o'clock position. Most guys I've worked with on this issue would call this hole round. It is not and shows bullet instability that will affect scores when the wind is twitchy and its speed is much more than a light breeze. The estimated bullet-yaw angle calculated using a methodology developed 5 or 6 years ago is 3.1 degrees. From test observations and hole measurements, a yaw angle over about 2 degrees starts to show-up in bullet trajectory tracking as unaccounted for flyers. My current thinking concerning optimum bullet stability is that a bullet that produces holes through the 1,000-yd target with no more than 1.5 degrees of yaw is where we want to be. A bullet yaw of about 1 degree is my target at this point in time. Certainly the 1.55" long Brooks ULRB will not produce top performance during challenging winds in long-range matches using an 18-twist barrel.
As you can now see and understand, the base of the bullet is not in line with the nose when the bullet passed through the target. Each of the pictures taken by Gerry showed a similarly elliptical hole. I'd say the same ULRB shortened to 1.50" would be just about right for a big 45 with an 18-twist. The 1.55" long version is for a 16-twist Shiloh that should be coming my way in the near future.
Another interesting test was shooting the Sharps LR bullet, originally 1.50" long, whose mold was shortened by 50 thousandths of an inch. Based on previous testing and confirmed by some computer simulations the 1.45" length looked about right for an 18-twist barrel. And, it was in spades. The holes punched through the target from the 1,000-yd line were all perfectly round. What a difference 50 thou can make. Holes made from the 1,000-yd line using the original length bullet (1.50") produced holes in the 6.5 degrees of yaw range. Note that the original length Sharps bullet had twice the bullet yaw compared to the longer ULRB. Nose design matters. The shortened bullet is 0.4460" in diameter and was patched with 7 lb tracing paper that mics at 1.4 thousandths. The bullets were wet-wrapped, dried and the patches dip-lubed. Here are the load stats:
45-90 Starline nickel brass
Accuracy was excellent from the 1K line. It also shot very well at 100-yds off-the-bench a few months ago. I like both to confirm potential for "shooting with the BIG DOGS" in matches.
If my 16-twist, 45-100 Shiloh with original Sharps PP chamber isn't ready for the American Creedmoor Cup the 13th & 14th of March the above will be the load used in that match. So far, it looks like quite a few of the guys will be shooting patched bullets during the match, and I know Michael Rix, the match director, will have some nice awards for those intrepid souls that seek to shoot back-to-the-past, the PP way.
Here's a picture of the shredded paper picked-up after testing. You can see a major difference between Arnie's (BACO bullet) and my paper. None of his scrapes had cut-marks all the way through, all of mine did. I currently believe this is one issue that should not be trivialized as IMHO the large scraps of paper indicate flyer potential.
The first 3 large scraps are Arnie's. The far left one has some rifling lines, but no cut-through, that was an inside wrap for sure. The other two are outside wraps. Mine are the skinny pieces of paper that are as wide as a land or groove. The bottom two pieces are the remnants of the paper folded-over the base. The left one has a "groove or land" scrap still attached. In the past, I've found some like that one that looked like a "star burst" with fingers of paper almost all the way around, very cool.
Finally, some results from Tark's and Gerry's testing. Gerry was shooting his recently purchased 45-100 Ball-wall launching the Paul Jones "Money Bullet." I pulled his target so can attest that for his last 8 shots of the below listed test load, only 1 round produced a 9, all the rest were 10's and X's. And, the vertical was about 1/2 the diameter of the X-ring. Man, that was some mighty fine shooting. And, he hit the spotter disk a couple of times. His best load was:
45-100 Starline brass
For the last target pulling session Arnie and I each pulled a target by ourselves as a few of the guys had taken leave early. Gerry was shooting on my target and finished before Tark, who was shooting on the target Arnie was pulling. Tark put one though the target and I happened to see a bit of wood fly and thought he'd scored a "Woody." Arnie couldn't find the hole so I went over to help him. After more target perimeter searching for the bullet hole we both saw what had happened at the same time. Tark had hit and splintered the spotter's wooden dowel. That means Tark put two consecutive bullets through the same hole from the 1,000-yd line with a 45-70 BPCR. That is some sure as sh^t, trick shooting pard. Arnie gave Tark the spotter as a souvenir. And, that load was shooting very well. I looked at his bullet impact tracking sheet later and 14 of the 15-shot string were in a horizontal line centered about X-ring high. Tark's load was:
Remington 45-70 brass
Well, that's enough writing for now. More testing to come as we'll have a LR practice match at the end of the month to tune-up for the American Creedmoor Cup and the SW WinterNationals Regional Creedmoor Championships the weekend following the ACC.
--- Dan Theodore, February, 2008