LiveLife

Yes. This is the truth. How about us doing some "black magic" unraveling/demystifying and get to the bottom of what causes "finished OAL variance" and how we can minimize it? First of all, what limits finished OAL? On a single stage press, it's the limits of bullet seating stem and the shell holder. As Yondering posted, resized case length variance has nothing to do with the finished OAL (But on a progressive press, it can so read on). Since most bullet seating stems do not push on the FMJ/RN/JHP bullet tip (For FP it can with flat stem) rather further down the bullet/ogive, if you experience finished OAL variance on a single stage press, it is likely from inconsistent ogive of the bullet. Bullets with more consistent ogive where bullet seating stem makes contact will produce more consistent finished OAL. On a progressive press, there is added variable of shell plate tilt/deflection that can add to the variance from bullet/ogive. When we resize a case, depending on how much expansion the case experienced and condition of brass (number of reloadings and amount of work hardening), different amount of force can be applied to the shell plate. You can rule out this variance by resizing the cases separately. Cases produce different amount of resistance to sizing because case wall thickness varies by headstamp and amount of expansion case wall experienced (Say light 9mm target load vs 9mm Major load), especially case base area where the brass is thicker, and apply varying amount of force on the shell plate during resizing. So using bullets with more consistent ogive will reduce finished OAL variance and with progressive press, you can try separately resizing cases to see if your finished OAL variance decreases. This thread demonstrates finished OAL variance of .001" using pre-resized brass of different mixed range brass and .003" variance of using un-resized brass - https://www.thehighroad.org/index.php?threads/myth-busting-pre-resized-brass-affect-on-oal-variance-progressive-press.833604/page-2#post-10779806 Here is a listing of case wall thickness .100" below case mouth by headstamp (where most of taper crimp is applied) - https://www.thehighroad.org/index.php?threads/myth-busting-neck-tension-and-bullet-setback.830072/page-3#post-10712225 Here is a listing of case wall thickness .200" below case mouth by headstamp (where most of neck tension is applied by the seated bullet base) - https://www.thehighroad.org/index.php?threads/myth-busting-neck-tension-and-bullet-setback.830072/page-3#post-10713822 FYI, due to much thicker case wall, neck tension at .200" below case mouth is much more significant than taper crimp applied at .100" below case mouth and why increasing the taper crimp won't necessarily increase/address neck tension issue. BTW, finished OAL consistency is not important if you experience bullet setback when the bullet nose bumps the feed ramp, which can significantly increase pressure. For me, what's more important than "finished" OAL consistency is "chambered" OAL consistency. I measure bullet setback by feeding/chambering dummy rounds (no powder, no primer) from the magazine and releasing the slide without riding it. Reducing/eliminating bullet setback will produce more consistent chamber pressures which affect muzzle velocities/SD. Case wall thickness directly affects neck tension and bullet setback and since 9mm bullet diameter can range from .354" to .356"+, if you experience significant bullet setback with your brass, you can consider using slightly larger sized bullets. Here's a listing of headstamp cases that experienced/did not experience bullet setback using .354' to .356" sized bullets - https://www.thehighroad.org/index.php?threads/myth-busting-neck-tension-and-bullet-setback.830072/page-4

IMHO, what I found with blow back action carbine testing that holds case mouth against the chamber just by recoil spring tension and combined weight of the bolt/buffer is that faster burn rate powder than W231/HP-38/Sport Pistol seem to burn powder granules more efficiently in the case before bolt/buffer moves back and start to leak gas from gap between case mouth and chamber (Hence why spent brass are often very sooty). So when slower burning powders (BE-86, etc.) did not produce optimal accuracy, I started testing with faster and faster burning powders. And for longer range 50-100 yards accuracy, lighter and lighter bullets to reduce bullet drop/vertical stringing. Reducing bullet weight from 124 gr to 115 gr to 100 gr RN bullet with 5.5 gr of W231/HP-38 (Hodgdon max load) produced around 2" 10 shot group at 50 yards (This group was comparably smaller than slower powder loads). And when I tested faster burning powders like Titegroup, Bullseye, Promo etc., Promo loads kept producing smaller groups than other faster powders (Yeah, I am beginning to believe Promo/Red Dot may be faster burning than Bullseye depending on bullet/seating depth/powder charge range) to the point of around 1.5" 10 shot group at 50 yards (smaller than slower burning W231/HP-38). 50 yard 10 shot groups with RMR 100 gr HM RN and W231/HP-38 and Promo (Thick plated bullet no longer in production now replaced with 95 gr FMJ and yes, mixed range brass). My groups are on par with what Guns & Ammo produced with their JR carbine at 50 yards (1.2"-1.7" shot groups). Promo load produced less muzzle velocity variance than HP-38 load and smaller 100 yard group. (1478-1475-1480-1471-1467 fps) When I pondered why Promo carbine loads were producing smaller groups as I do not get smaller groups with Promo loads when shooting them out of pistols, light bulbs went off: Locked breech pistol (1911, Glocks, etc.) compared to blow back (Makarov, etc.) holds case mouth against the chamber for quicker pressure build which ensures more efficient powder burn (even for slower burning powders). But blow back action carbines will produce comparably more efficient powder burn with faster burning powders to hold case mouth against the chamber longer, which in turn produce more consistent muzzle velocities (for lower SD) and less bullet drop/scatter on target (vertical stringing) And large flake Promo easily produce 100% case fill loads (Depending on OAL) compared to other dense powders that become "powder forward" when the round is chambered and primer flash must jump the air gap to ignite powder granules compared to Promo load where powder granules are in contact with primer flash. So when applicable, I will use shorter OAL that will ensure 100% case fill. Another thing to consider if you are using AR PCC is the combined bolt/buffer weight for longest "in battery/dwell" time. With carbine recoil spring, I found 19-22 oz combined weight of buffer and bolt produces more comfortable felt recoil. 16-18 oz combined weight produces harsher felt recoil. And consider heavier buffer weight for longer in battery/dwell time to allow powder to burn longer to build chamber pressures (and this also decrease amount of soot on the case). PSA bolt 14.7 oz + PSA buffer 5.3 oz = 20 oz combined weight and produces comfortable felt recoil with various 9mm loads. For longest "in battery" time for more consistent chamber pressures, use heaviest buffer that will reliably cycle the bolt. With 20 oz combined weight, my PCCs will cycle even lighter target loads (115 gr RMR FMJ with 4.6 gr W231/HP-38 or 4.0-4.2 gr Red Dot/Promo). For reference: - H1 buffer weighs 3.8 oz - H2 buffer weighs 4.6 oz - H3 buffer weighs 5.4 oz BTW, W231/HP-38 is temperature sensitive and Promo is reverse temperature sensitive. Here are chrono number difference between 56F and 79F: 115 gr RMR HM RN 4.8 gr W231/HP-38 @ 1.130": 1275-1263-1253-1290-1248 fps (56 F - JR carbine) 115 gr RMR HM RN 4.8 gr W231/HP-38 @ 1.130": 1303-1289-1298-1311-1323 fps (79 F - JR carbine) 100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1478-1475-1480-1471-1467 fps (58 F - JR carbine) 100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1458-1450-1445-1442-1448 fps (71 F - JR carbine) Last edited: Saturday at 5:32 P

ELEY USA: Shooting ELEY .38 Super Comp at the Big Country Tactical steel match ELEY USA: Most people don't realize it, but using ELEY actually increases your shooting speed by 10% (Really?)

Some videos from RMR facebook page of making "ELEY match bullet" production process - https://www.facebook.com/rmrbullets/photos/a.164961740263755/2345674178859156/?type=3&theater Here, Jake talks about keeping lead core weight consistency to +/- 4/10th of a grain (Measured weight variance more typical of less than 0.5 gr total) The birth of the match bullet. It all starts with the core. If your lead is consistent then your bullet will be too Where it all begins Production process

I agree that there are many other good choices.

Thank you. I tried to use "bds" for this forum which are my dogs' initials (Blaze, Daisy and Steffie) but somehow it didn't take (I can't remember now why) and kks took (my daughter's name and my previous dogs Kimberly and Sammy). * Sigh * In hindsight, I should have picked a more mundane first thread to post like case wall thickness and resulting neck tension/bullet setback you guys could all reference - https://www.thehighroad.org/index.php?threads/myth-busting-neck-tension-and-bullet-setback.830072/page-4

BTW, WST is reverse temperature sensitive and if you developed your loads in colder winter, your velocity will be lower in the hotter summer - https://www.thehighroad.org/index.php?threads/question-on-temperature-sensitivity.817116/#post-10473222

Oh no. I am not the manufacturer who is "longdayjake" on THR. I am "bds" on THR. We have seen him go from pre law school days selling bulk/closeout/blemished bullets on the side to become a true "mom and pop" American dream and celebrated together when he first bought a refurbished bullet making machine. I have been a reader/lurker since 2013 and had planned to start posting after retirement this year and ELEY/RMR news happened to be my first post ... sorry, not intentional.

GrumpyOne, Thanks for the PM and the warm welcome.

I was just trying to validate my identity as a longtime poster on a gun forum in reloading category and my efforts to "myth bust" using factual objective repeatable measurements (As much as possible as I am human and still learning) while focusing on helping other members/reloaders solve their reloading issues.

I am member "bds" on THR. While I have been lurking those years on BE but posting actively on THR. I was a medic in the Army and spent last 24 years in CA state government service and retired this year (July 4th!!!) and these are my various "myth busting" threads where I "try" to get to objective facts and pending retirement projects - https://www.thehighroad.org/index.php?threads/thr-group-project-pistol-advanced-reloading-concepts-and-discussions.778197/page-10#post-10966692 If you are member of THR, moderator Walkalong can vouch for me (I can send him a PM as to kks ID on BE) A quick search on THR Handloading and Reloading category should reveal who I am (My noted thread which helped many many reloaders since the component shortage days) - https://www.thehighroad.org/index.php?threads/where-are-there-reloading-components-on-sale.707473/ All of my threads on THR - https://www.thehighroad.org/index.php?search/38659936/

Quote from Guns America Digest article - https://www.gunsamerica.com/digest/rmr-9mm-124-jhp-mpr-review/?utm_source=email&utm_medium=20190708_BlogDigest_336&utm_campaign=%2Fdigest%2Frmr-9mm-124-jhp-mpr-review%2F&fbclid=IwAR0px_E2pxIBTpEGsu3J1xLvk86kfwopr2zmXyU2jlAL_2Ij3-hskEk4PtI "As we can see the RMR 9mm 124 JHP’s produced exceptional results. I have tested many different bullets out of my Infinity so I know what my gun is capable of."

Looks like ELEY will be showcasing the new round in September so we'll get to see how it performs soon enough - https://www.killoughshootingsports.com/index.php/ammo/eley/action-38sc/eley-38-super-comp-124-gr-fmj-rn-major.html "ELEY will be showcasing the new round at the European Handgun Championships in Serbia this September as well as the ELEY ammunition Area 59 championship in November."

That's true. But ELEY could have chosen any match bullet of their choice. Chances are, fact that ELEY chose RMR bullet may be because during their testing and evaluation, RMR bullets were more consistent and produced smaller groups. Perhaps.

May depend on the OAL/COL used. To be sure, do some case fill calculations to see if you are going to end up with a compressed load - https://www.thehighroad.org/index.php?threads/wst-in-9mm.854647/#post-11199933 I measured several 9mm RMR 124 gr FMJ RN and longer bullets measure .598" So using OAL/COL of 1.135", my max case fill is: OAL - Bullet length = 1.135" - .598" = .537" I measured some resized WIN cases and I got .747" as average resized case length. So I subtract max case fill from average resized case length and I get .747" - .537" = .210" I used the end of my dial calipers to mark the inside of the case and filled it with WST to mark and weighed the charge - 4.6 gr. So for .598" length 124 gr RN bullet loaded to 1.135" OAL, max charge of WST before powder compression is 4.6 gr. This is in line with what CocoBolo posted who I follow -