Suppressor POI change question

[John from MD]

Today I was shooting my 300 BO pistol with 8 inch barrel using my Palidin 300 suppressor at 50 yards. I got about a 2 inch change (higher) in POI from when I shoot supers.

My supers are 150gn with 16.5 gns of H-110 and my subs are Berry 220gn with 10.5 of H-110.

If I was to shoot 150gn at sub velocity, will this bring my two groups together?

 

[Doco Overboard]

I bet the heavier of the two bullets will print higher at the same velocity if that’s what your after.
Only because jump /recoil would be greater, and the heavier bullet at 50 yds retains velocity to a higher degree.
Not sure what bearing the suppressor would cause, I’m not familiar with their use or how to apply them currently for my needs.

 

[outrider58]

2" @ 50 yards seems a bit extreme. I think you could achieve better results using a different powder along with lighter (190-208) bullets in your subs. I'm getting about an inch difference, if that with my loads at 50. It's been a while since working up different loads though. Just going off memory. My 10.5 sbr has a bdc reticle, which makes ranging easier.

 

[John from MD]

2" @ 50 yards seems a bit extreme. I think you could achieve better results using a different powder along with lighter (190-208) bullets in your subs. I'm getting about an inch difference, if that with my loads at 50. It's been a while since working up different loads though. Just going off memory. My 10.5 sbr has a bdc reticle, which makes ranging easier.

I have some 1680 which I've been told works better with subs so I will work something up over the winter. I am using a red dot sight so I can't really work it like you would a scope with a bdc reticle. I'm also going to try 1680 with my 150's and see how they do. I only use this as a range toy so it isn't very critical.

 

[outrider58]

I have some 1680 which I've been told works better with subs so I will work something up over the winter. I am using a red dot sight so I can't really work it like you would a scope with a bdc reticle. I'm also going to try 1680 with my 150's and see how they do. I only use this as a range toy so it isn't very critical.

I think you have the right idea, though I have never tried 1680 on supers. Lil Gun has been my mainstay for supers, but I have not tried it on pills above 135gs.

1680 seems to have the least variations with subs. Very easy to 'dial it in'.

 

[outrider58]

I bet the heavier of the two bullets will print higher at the same velocity if that’s what your after.
Only because jump /recoil would be greater, and the heavier bullet at 50 yds retains velocity to a higher degree.
Not sure what bearing the suppressor would cause, I’m not familiar with their use or how to apply them currently for my needs.

Pretty much, 300Blk is not a punchy round, super or sub wise. I doubt there is much consequence from recoil. John is an expert shooter.

 

[John from MD]

Pretty much, 300Blk is not a punchy round, super or sub wise. I doubt there is much consequence from recoil. John was an expert shooter.

Thanks but everyone gets old and I no longer can shoot like I once did. However, my testing was done from the bench and it didn't have anything to do with gun or shooter movement.

I will say I was surprised at the groups I was getting with the Berry bullets. I put five into a 1 inch group which is better than when I tried their bullets years ago in a 7.62x39 CZ.

 

[Doco Overboard]

Pretty much, 300Blk is not a punchy round, super or sub wise. I doubt there is much consequence from recoil. John is an expert shooter.

All firearms recoil, jump and are subject to flip. Understanding how internal ballistic properties equate into external results is expert territory.
Because the OP is asking the question, its obvious he's there and probably has been for some time I think.
Sometimes identical cartridges that are carefully loaded, have differing PoI's at short range, but when fired at a longer range they coincide when the groups are examined for performance.
The term used to describe/graph the trajectory and how it relates to line of sight and prolongation of bore axis is known as compensation.
Weight and velocity of the projectile combined with physical properties of the firearm design and working characteristics are the determining factor.
Shooter error comes into play during the transition from internal, to external ballistics.
John from MD is just not an expert shooter, he's a ballistician.
Probably one of the best questions Ive seen posed on the forum for some time.
IMHO.

 

[John from MD]

Well, I did try to read this once.

 

[Doco Overboard]

I read the same or similar things sometimes, the second textbook is easier for me to understand becuase it has color pictures and sometimes connect the dots!

 

[John from MD]

I read the same or similar things sometimes, the second textbook is easier for me to understand becuase it has color pictures and sometimes connect the dots!

 

[rayrevolver]

John, I bought 1000 projectiles, 190gr Nosler CC, to start reloading 300BO subs. At the time, the 190s were the lightest most folks were loading.

Send me a PM if you are interested in buying/trading.

 

[dannyp]

Thanks but everyone gets old and I no longer can shoot like I once did. However, my testing was done from the bench and it didn't have anything to do with gun or shooter movement.

I will say I was surprised at the groups I was getting with the Berry bullets. I put five into a 1 inch group which is better than when I tried their bullets years ago in a 7.62x39 CZ.

berrys are good bullets , very concestent i my opinion

 

[outrider58]

All firearms recoil, jump and are subject to flip. Understanding how internal ballistic properties equate into external results is expert territory.
Because the OP is asking the question, its obvious he's there and probably has been for some time I think.
Sometimes identical cartridges that are carefully loaded, have differing PoI's at short range, but when fired at a longer range they coincide when the groups are examined for performance.
The term used to describe/graph the trajectory and how it relates to line of sight and prolongation of bore axis is known as compensation.
Weight and velocity of the projectile combined with physical properties of the firearm design and working characteristics are the determining factor.
Shooter error comes into play during the transition from internal, to external ballistics.
John from MD is just not an expert shooter, he's a ballistician.
Probably one of the best questions Ive seen posed on the forum for some time.
IMHO.

I read this, but I'm no smarter for it...

 

[Doco Overboard]

I read this, but I'm no smarter for it...

What its about, is internal and external ballistics,
and compensation of course.
Compensation, the ability for two like cartridges to have differing trajectory's at a short range due to specific firearm characteristics inherent in all small arms systems, but mean point of impact producing a similar sheaf of fire or proportional probability POI at a greater range from similar issuance and delivered by the same system.
Its actually pretty old subject matter but not often discussed in you tube or popular gun rags.
A subject more often discussed where sales or hits are not the pitch.
Probably the best place to become familiar is a book, preferably written by someone who has lots of money and education behind them and has worked or written/produced formulas both mathematical and practical for an arsenal or gunnery school.
I dont have any gifs, just examples of the literature and a smidgen of experience loading for, building and shooting obsolete junk.