Another TCU test run

[Panhandle]

The 6.5 TCU has been working so well that I’m going to try a 6 TCU. Most data is out of date and doesn’t list a number of more modern powders that I believe will safely add some performance to the little cartridge. I had not realized the case capacity is about equal to a 6 PPC which does have data listed that’s more up to date. The starting data for the 6PPC as well as any data for the 6x45 should offer plenty of starting options. With Ram weight bullets I believe it will safely run less than 100fps behind the 6BR. Ted Ulmer is threading and Chambering a Patriot Valley Arms barrel for me now. If all goes well I may be able to give it a test run at the Oklahoma Regional next month. Always fun to try something new.

[Allen Corneau]

Wayne,

Do you think you can get the heavy bullets going fast enough to have the down-range energy to knock over the rams?

Glad to hear you'll be at the Tulsa Red Castle match. See you there!

[Panhandle]

I don’t know the answer. I think like the 6BR it will be marginal only a little more so. The energy is there it just doesn’t get put to use when it hits the targets. Gets into the world of momentum, mass and bullets dwell time. My little .357 with its 200gr bullet going 1080 knocks over the same rams with under 400 foot pounds of energy at half the distance. The 110-115 class bullets from the TCU will deliver twice that amount of energy at the HP Ram line but don’t have the mass to get it done. I’m hopeful that the 6mm bullets going a little slower won’t suffer any performance loss over the same bullet going a little faster from the BR. Maybe at the slower speed they will survive a little longer on the target to get the work done. If time allows I’ll test my theory at Whittington before the Oklahoma match. Worst case, I get kicked less, shoot better and cry in my margaritas about the Rams that didn’t fall.

A bullet design that could deliver its mathematical energy onto our targets would change our world but I think in our current world the mass of a 6.5 is needed to be more reliable.

[Allen Corneau]

A bullet design that could deliver its mathematical energy onto our targets would change our world...

Now you got me thinking that a ~110 grain monolithic bullet would a good candidate for a Ram-killer.

🧐

[Panhandle]

We are thinking along the same lines. I will test all the heavy conventional bullets but some 95gr monolithic target bullets are halfway to my house from PA. The 100gr was out of stock. Having no lead in them they are long for the weight giving high BC’s and perhaps more time to push the target over as they collapse on its face. I’m only slightly optimistic. To my surprise when you watch them strike steel they appear to behave much like a conventional bullet. They cause no target damage and end up looking like a .22 or pellet after hitting a target, just a little disc of metal. All the math, ballistic studies, slow mo film and head scratching can’t provide the conclusion we need. They need to be tested specifically on the targets we shoot. More than likely I’m trying nothing that some fellow silhouette shooters haven’t already tried. I enjoy the research and like watching a movie someone else has already scene, don’t tell me how it ends. I will know soon enough.

[Varner1808]

I'm interested in the accuracy of the Patriot Valley Arms barrel. Please post your results.

[Panhandle]

Will do. What I know so far; it was in stock, shipped fast and upon inspection Mr. Ulmer wrote me and said “looks like a very nice barrel”. I will follow up with more information once I get to put some bullets down the barrel.

[Panhandle]

Second barrel update for Varner1808. Received the 1-7 twist PVA barrel and installed it yesterday. The factory recommended a 15 shot break in, shoot 5 then patch clean with Bore Tech, repeat three times. While cleaning it was easy to notice the barrel is smooth as glass, no tight or loose spots. It also seems it will likely shoot well but that was not this drill. I used a middle of the road load of 23g IMR 4895, federal necked up military 5.56 brass and 107gr sierra. Very lucky 200 yard bore sighting job of looking down the bore and adjusting the scope to look at the same place. First shot landed 4” from my aiming point. The 15 shot group was 1.78”, the first few shots and a shot or two or three after each cleaning would be fliers slightly high and left (good to know) leaving me with an 8 shot group of .61”.

two other notes. I had never used Bore Tech, I liked it, eats copper and smells like hand soap. I need to get some non-copper jags.
used a little Garmin radar chronograph. what a magic little device and super convenient, especially at a public range.

[Panhandle]

1808 - after a good deal of testing I would say the PVA barrel is at least equal to any other barrel I have used from other highly respected barrel makers. It cleans easy, has a very straight concentric bore and is accurate.

Allen - the PVA 90g monolith had a 6 out of 10 Ram performance at 2650fps, the 90g Swift the same. That was a very mild starting load. I think I have another 100fps left in the tank. I would like to test the 100gr version and think I can obtain about the same 2650’ish. Be interesting to see which performs better a 90 at 2750 or 100 at 2650. That takes time and access to Rams, my guess is I’ll never get around to it. My current focus is testing powders that will give me all I can get out of the 112-115 class bullet. They are available and less expensive. I’ll use the same heavyweight at around 2200 for chickens and pigs. Just like with the 6.5TCU, A5744 is providing mild, accurate loads with very low ES and SD. For top end ram loads It’s a slow process with no modern powder data for the TCU family. I’ve been cautious using starting data (or lower) from a few modern 6mm cases with very similar case capacity.