9mm: .357" bullets in a .355" gun?

Testing a load for which there is no data.
Tisas 1911 Tank Commander 9mm has a bore diameter of .3571" and a land diameter of .348"
testing 110 grain .3575" Hornady XTP jacketed hollowpoints in the 9mm with Titegroup powder, Fiocci small pistol primers and mixed brass
seated to 1.080-1.085" and a Lee factory crimp die seat to "heavy"

[@STMwoodturning]

I used Titegroup in a 9mm years ago. I was able to run 4.5 grains in my G17 with no issues. Increasing the charge might tighten up the groups as well.

[@timberfallingcouple]

Hey thanks for adding to this! I appreciate it greatly! I'll work up to it and see if it likes it

[@STMwoodturning]

@@timberfallingcouple be sure to check for all the usual signs of high pressure. 4.5 was ok in my firearm but… However, I think you’re cautious and demonstrate good judgement. Reliability is king over power

[@jesusislord7733]

Titegroup is fine it is as fluffy and have the case fill like i usually want but still uses a low amount per rd. There is around 7000 grs in 1lb of powder. 7000÷5(grs per rd)=around 1400rds per lb
7000÷4.5 (grs per rd) = 1550 rds per lb
^ thats why i dont waste my blue dot and other hard to get powder at 8-9 grs per rd.

[@jesusislord7733]

Zero bullets sell bulk. 355, .356 (super), and .357 diamater bullets that will run fine in semi auto glock style pistols and ars. I like around 5 grs of Unique for 115 to 124/125 gr's. Bullseye, and Universal works similarly

[@Dave_9547]

Bullet diameter is often not too critical. I shoot a 1911 chambered in .38 Super, which is supposed to be .356 bore. Regular 9mm bullets at .355 are very accurate. Sorry no target to show.

[@timberfallingcouple]

I appreciate all of the insight guys have on the reloading stuff. The only way to learn what ain't written in a Lyman manual is from guys who done it

[@rbm6184]

9mm: .357" bullets in a .355" gun?
I have and do load .357 diameter 9mm bullets for .38Spl. but not .355 diameter 9mm bullets for .38Spl. The .38Spl. needs that .357 diameter and 9mm doesn't. My 9mms hate .357 diameter bullets so I put them to use in .38Spl. It depends on the bore diameter. 9mm is suppose to be .355 and they will shoot .356 but they do not like .357. .38Spl. is suppose to be .357 and smaller diameter may not perform well. Accuracy and bullet spread is affected by diameter. If your 9mm is .357 then its not a .355 gun. Your powder charge is too low causing your cycling problems. I use Unique powder mostly for all my pistol loads, occasionally Bullseye but Bullseye has a faster burn rate and its dirtier than Unique. Unique is cleaner burning with a medium burn rate and I can also use it for my shotgun shell loads. Most pistol powders don't allow for use in shotgun shells. All guns have a specific bullet weight that they are factory zeroed to so you might want to look that up for each of your guns. Most European 9mms for instance are factory zeroed for 124gr. NATO while "most" US 9mms are factory zeroed to standard 115gr. Most .38Spl.s are factory zeroed to 158gr. but some to 148gr. Most .45ACPs are factory zeroed to standard 230gr. and so on. The factory zero will affect point of impact by bullet weight. A light for caliber bullet usually has faster velocity and it will print low while heavy for caliber with lower velocity will print high.

[@timberfallingcouple]

I really like that you mentioned that thing about heavy for caliber printing higher than light for caliber. I think a lot of folks haven't shot enough to consider that.

[@seantbr2019]

What about running some 158gr ? Would it be to long ?

[@timberfallingcouple]

I think it would fit, but the load data seems a little scary. Guys saying it could make for a compressed charge even with this really fast powder etc