Fidot
Member
- Joined
- Dec 30, 2020
- Messages
- 6
Howdy there folks!
Long time lurker, first time poster.
Have been reading copious amounts of text in the past some months, and learning about reloading - including lots and lots of topis on this forum. Finally, I think I want to start actually doing something.
My victim round is going to be 9mm, and my current components of choice and availability (under my desk) are Titegroup, RMR 124 Truncated Cone FMJs, and some 9mm brass to be put together for my 1911 (I am sorry for putting 9mm thru a 1911 but ... I didn't know any better when I bought it ).
Here are the bullets: https://www.rmrbullets.com/shop/bul...gr-rmr-truncated-cone-flat-point-matchwinner/
Additionally, I do have a bag of RMR's hollowpoint in the same 124 grain (https://www.rmrbullets.com/shop/bul...hollow-point-multi-purpose-round-bullets-new/), which will become important in a moment.
I am sorry upfront for somewhat a ranty post.
I did read other topis on the subject here, specifically these guys, which aided my thinking:
https://www.thehighroad.org/index.php?threads/need-help-with-124gr-rmr-matchwinner-load-data.869112/
https://www.thehighroad.org/index.php?threads/sport-pistol-in-9mm.846103/
So, of course, having picked a bullet that's "unlisted" in Lyman, Hornady (ha!) and pretty much anywhere else, and from a manufacturer w/o load data, I have been trying to figure out my OALs and my charges.
The goal of this is to play at the range - and I would love to make this round accurate enough to practice up to 50 yards.
So first of, the charge.
From my understanding and common sense, charges listed for bullets are substitutable as long as:
- I am picking charge for the same material and jacket presence (ie, copper jacketed bullets are one category, cast are other, and plated are third out of three big ones).
- I am picking charge data for the same bullet diameter (read on - I had a fun epiphany)
- I am picking charge data for the same or larger weight bullet as mine. That last bit came from one of the pamphlets in one of the Lee diesets I have and it makes sense - heavier bullet charge data will assume less available "charge space", so you're not increasing pressure with using a heavier bullet charge data with a lighter bullet. Also, loading manuals seem to reduce powder charges with increase of bullet weights of the same type across the same powder type for at least the few data I have reviewed extensively (45C, 357Mag, and 9mm).
- I am ensuring that the "charge area" volume (space inside the case where my powder is) is the same or larger than the one in listed data.
--
Now, if I was to load RMR hollowpoints that I have, I would've used XTP data from Lyman book (for some reason Hodgdon's (and therefore Lee's), and Hornady's books don't list Titegroup charges for 124 grain bullets).
Now, Lyman. 3.8-4.1 grains for 124 XTP bullet. Oh, also the same charge range for 125 GR "HAP" bullet, but they seat it .015 further out (1.075 vs 1.060 COAL) so I guess they keep the same "charge space" and ignore 1 grain weight difference.
What gives a bit more confidence for using this specific data is 125 grain Sierra FMJ data from Hodgdon - with 1.090 COAL and 4.1-4.4 grains - though the reason why the charge "shifted" so much would probably be increase of "charge space" volume (FMJs would be shorter than hollowpoints, and they're seating it further out).
Browsing thru Lee's data, I find a red flag - Titegroup for "125 grain Jacketed bullet" listed 2.8-3.2. ??!?!. This directly contradicts Hodgdon, and logic - more "charge space" volume, smaller charge?
That was a headscratcher for a while, until I noticed an entry for Hornady HAP on Hodgdon's site: listing that same charge and COAL. The culprit? Bullet diameter for HAP is 0.356. Mine are .355, and Lyman and Sierra data is for .355 bullets as well. So I feel safe disregarding this much lower charge recommendation.
So now, to sane COAL
Lyman's hollow point lists 1.060 for that 3.8-4.1 charge. Is it safe for me to use this as a minimum?.
I am stipulating here that Hornady's XTP bullet used for Lyman's COAL data is going to be longer than mine, and therefore, I will have more "charge space" volume available - so using Lyman's charge + COAL I will be in the "safe zone".
Why?
Hornady's XTPs are "conical" - I have some in 115 grain / .355 here and they are. But there's a hole in the XTP - meaning that either the cone will be longer, or the base will be longer.
So therefore, seating mine to 1.060+ should be fine.
Couple "confirming factors" here.
Hornady's book is useful in one important regard - it has full size pictures of bullets - including that same XTP that Lyman uses in theirs. I wouldn't put calipers to it, but I can ascertain roughly "bigger/smaller" and such. I have some 115 grain XTPs and it matches it's picture in the book perfect. By the way, wouldn't it be nice to have dimensional drawings for all the bullets? Sigh.
My bullet is shorter than 124 grain XTP, visually, when lined up with the picture; so therefore, it will seat less deep, giving a larger volume in the "charge space" than XTP.
And guess what? It matches perfectly with Hornady's (marked as discontinued) FMJ-FP #35567B - and while Hornady's book does not list charged for TiteGroup for 124 grain bullets, their 124 grain XTP shares the same load data with their FMJ-FP! And they seat it at 1.050 which is 10 thou less than what I'm planning using Lyman's XTP data (note that Lyman's XTP data matches COAL to Hornady's).
Will I have enough bullet engagement in the case?
My bullet is .550 - my brass is .745 (it's once fired), so 1.060 - .745 = 0.315 "stickout", with .550-.315 = .235 of the bullet in the cartridge.
Mr. McPherson in his "Metallic Cartridge Handloading" notes the reasonable minimum to be generally 1/2 bullet diameter - which means I have additional .057 (.235 - (.355/2)) to play with on the long side (assuming no chambering / feeding / "rounds shortening and bullets seated deeper" while chambering", exceeding SAAMI spec issues of course).
So bottom line is, seems that my brackets are 3.8 - 4.1 grains of TiteGroup with 1.060 - 1.117 COAL.
I would very much appreciate y'alls comments on my conclusions and approach...
Long time lurker, first time poster.
Have been reading copious amounts of text in the past some months, and learning about reloading - including lots and lots of topis on this forum. Finally, I think I want to start actually doing something.
My victim round is going to be 9mm, and my current components of choice and availability (under my desk) are Titegroup, RMR 124 Truncated Cone FMJs, and some 9mm brass to be put together for my 1911 (I am sorry for putting 9mm thru a 1911 but ... I didn't know any better when I bought it ).
Here are the bullets: https://www.rmrbullets.com/shop/bul...gr-rmr-truncated-cone-flat-point-matchwinner/
Additionally, I do have a bag of RMR's hollowpoint in the same 124 grain (https://www.rmrbullets.com/shop/bul...hollow-point-multi-purpose-round-bullets-new/), which will become important in a moment.
I am sorry upfront for somewhat a ranty post.
I did read other topis on the subject here, specifically these guys, which aided my thinking:
https://www.thehighroad.org/index.php?threads/need-help-with-124gr-rmr-matchwinner-load-data.869112/
https://www.thehighroad.org/index.php?threads/sport-pistol-in-9mm.846103/
So, of course, having picked a bullet that's "unlisted" in Lyman, Hornady (ha!) and pretty much anywhere else, and from a manufacturer w/o load data, I have been trying to figure out my OALs and my charges.
The goal of this is to play at the range - and I would love to make this round accurate enough to practice up to 50 yards.
So first of, the charge.
From my understanding and common sense, charges listed for bullets are substitutable as long as:
- I am picking charge for the same material and jacket presence (ie, copper jacketed bullets are one category, cast are other, and plated are third out of three big ones).
- I am picking charge data for the same bullet diameter (read on - I had a fun epiphany)
- I am picking charge data for the same or larger weight bullet as mine. That last bit came from one of the pamphlets in one of the Lee diesets I have and it makes sense - heavier bullet charge data will assume less available "charge space", so you're not increasing pressure with using a heavier bullet charge data with a lighter bullet. Also, loading manuals seem to reduce powder charges with increase of bullet weights of the same type across the same powder type for at least the few data I have reviewed extensively (45C, 357Mag, and 9mm).
- I am ensuring that the "charge area" volume (space inside the case where my powder is) is the same or larger than the one in listed data.
--
Now, if I was to load RMR hollowpoints that I have, I would've used XTP data from Lyman book (for some reason Hodgdon's (and therefore Lee's), and Hornady's books don't list Titegroup charges for 124 grain bullets).
Now, Lyman. 3.8-4.1 grains for 124 XTP bullet. Oh, also the same charge range for 125 GR "HAP" bullet, but they seat it .015 further out (1.075 vs 1.060 COAL) so I guess they keep the same "charge space" and ignore 1 grain weight difference.
What gives a bit more confidence for using this specific data is 125 grain Sierra FMJ data from Hodgdon - with 1.090 COAL and 4.1-4.4 grains - though the reason why the charge "shifted" so much would probably be increase of "charge space" volume (FMJs would be shorter than hollowpoints, and they're seating it further out).
Browsing thru Lee's data, I find a red flag - Titegroup for "125 grain Jacketed bullet" listed 2.8-3.2. ??!?!. This directly contradicts Hodgdon, and logic - more "charge space" volume, smaller charge?
That was a headscratcher for a while, until I noticed an entry for Hornady HAP on Hodgdon's site: listing that same charge and COAL. The culprit? Bullet diameter for HAP is 0.356. Mine are .355, and Lyman and Sierra data is for .355 bullets as well. So I feel safe disregarding this much lower charge recommendation.
So now, to sane COAL
Lyman's hollow point lists 1.060 for that 3.8-4.1 charge. Is it safe for me to use this as a minimum?.
I am stipulating here that Hornady's XTP bullet used for Lyman's COAL data is going to be longer than mine, and therefore, I will have more "charge space" volume available - so using Lyman's charge + COAL I will be in the "safe zone".
Why?
Hornady's XTPs are "conical" - I have some in 115 grain / .355 here and they are. But there's a hole in the XTP - meaning that either the cone will be longer, or the base will be longer.
So therefore, seating mine to 1.060+ should be fine.
Couple "confirming factors" here.
Hornady's book is useful in one important regard - it has full size pictures of bullets - including that same XTP that Lyman uses in theirs. I wouldn't put calipers to it, but I can ascertain roughly "bigger/smaller" and such. I have some 115 grain XTPs and it matches it's picture in the book perfect. By the way, wouldn't it be nice to have dimensional drawings for all the bullets? Sigh.
My bullet is shorter than 124 grain XTP, visually, when lined up with the picture; so therefore, it will seat less deep, giving a larger volume in the "charge space" than XTP.
And guess what? It matches perfectly with Hornady's (marked as discontinued) FMJ-FP #35567B - and while Hornady's book does not list charged for TiteGroup for 124 grain bullets, their 124 grain XTP shares the same load data with their FMJ-FP! And they seat it at 1.050 which is 10 thou less than what I'm planning using Lyman's XTP data (note that Lyman's XTP data matches COAL to Hornady's).
Will I have enough bullet engagement in the case?
My bullet is .550 - my brass is .745 (it's once fired), so 1.060 - .745 = 0.315 "stickout", with .550-.315 = .235 of the bullet in the cartridge.
Mr. McPherson in his "Metallic Cartridge Handloading" notes the reasonable minimum to be generally 1/2 bullet diameter - which means I have additional .057 (.235 - (.355/2)) to play with on the long side (assuming no chambering / feeding / "rounds shortening and bullets seated deeper" while chambering", exceeding SAAMI spec issues of course).
So bottom line is, seems that my brackets are 3.8 - 4.1 grains of TiteGroup with 1.060 - 1.117 COAL.
I would very much appreciate y'alls comments on my conclusions and approach...
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