Looking for a subsonic, gentle shooting 147 gr round for a PC Carbine.

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JW85

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Currently have Campro 147gr RNFP bullets and hoping to make some low-power rounds for steel plate and target shooting within 50m.

Goal is lower noise and recoil but still reliable in cycling the PCC and without risking any kind of stuck shot.

I've got CFE pistol and TG powder available.
 
CFE Pistol produces higher pressures than TG for the given load range of 9mm Subsonic with 147gr bullets. Search out the "Hogdon reloading data center", input the necessary parameters for the particular cartridge and see the results. The trick will be keeping the velocity subsonic in a PC barrel, while creating enough pressure to cycle the action. You may need to experiment with powder selection to accomplish this.
 
Pulling in some data:
Campro data (currently offline but referenced at Shooter's Reference) indicates 3.7-4.2 gr of CFE pistol /w the Campro 147 Gr @ 1.090".

Hornady shows 3.3-4.3gr with a 147 gr FMJ-RN-BT bullet for CFE pistol at 1.165". COL difference makes sense considering the flat nose of the Campro vs the RN. Max is almost identical, may stick with the Campro Max of 4.2 but try loading down closer to the Hornady minimum for testing.

So thinking 3.3gr-4.2gr CFE at 1.090" with the Campro 147. Hornady predicts 700fps for 3.3 gr and 900 for 4.1 gr but that's from a pistol barrel. PCC will add some velocity but how much will be the question.

If the lower range cycles the action well I will likely just stay there. Even if the longer barrel gains 200 fps (which is probably an overestimate), most of these loads should be firmly subsonic.
 
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For noise, what matters is the pressure as the bullet leaves the barrel, right?

So for quieter loads, in theory go with the fastest powder, lightest charge that will reliably cycle the action.

But you've got several variables moving about so if I were in your shoes I'd just try working down ladders of both powders. If you get beyond the minimum book charges, be damn careful about going any further of course.

I'd use magnum primers to try to get to peak pressure earlier, and to worry less about inconsistent ignition in reduced loads.

I doubt you'll get anywhere near 200fps gain with the longer barrel.
 
It's funny you mentioned the Magnum primers, I was able to find some local but was a little nervous to use them. From the research I've done it seems that the pressure should only be an issue if you are already at the upper end of loading - which of course I'm not planning on for these.

I too think 200 fps won't be happening, probably closer to half that.
 
JW85 said:
It's funny you mentioned the Magnum primers, I was able to find some local but was a little nervous to use them. From the research I've done it seems that the pressure should only be an issue if you are already at the upper end of loading - which of course I'm not planning on for these.

I too think 200 fps won't be happening, probably closer to half that.
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No worries, magnum primers are just a different data point. Work up your load a little more conservatively than usual - But since you're working "down" a ladder, it's probably no sweat.

Some loads see higher ES with magnum primers, and some lower. Watch your data, and I'd only worry about high ES if you decide to set your load much lower than recommended in the books (or as you say at max pressure loads, but that's not what you're doing here).

If you get a very early peak pressure in your burn, you might see very small gains from the longer barrel. This is what you want though, for quieter loads.

Let us know how it goes!
 
Thanks, appreciate the input :)

Going to test out 3.5-4.1 in 0.1 increments for CFE and 2.8-3.3 in 0.1 increments on Titegroup. Five shots at each charge weight.

Both of this dip a bit deeper than the Campro minimum but within what Hornady seems to be suggesting as low-range for a similar load. Will load to Campro recommended length of 1.090" and use Magnum Small Pistol primers.
 
3.3 to 3.4gr titegroup. But I would still suggest 124gr around 1030 to 1050fps. Just as quiet and less chance of the bullet staying in the barrel.
 
FarmerDanz said:
3.3 to 3.4gr titegroup. But I would still suggest 124gr around 1030 to 1050fps. Just as quiet and less chance of the bullet staying in the barrel.
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Do you think there's much chance of running that risk with the 147s at the charge levels I've noted?

Don't want to run that risk and like the idea of the heavier bullet if staying subsonic. Plus I already have the 147s and want to use them :)
 
Decided to start off with the CFE 3.5-4.1 with Magnum SP primers. Will be keeping very close eye on cycling and barrel clearing at lower charges.

Thankfully the PC Carbine is very easy to examine the bore due to the takedown feature. Even my lowest load is still within the lower range of what Hornady recommends for CFE in their 147 gr load category though.

https://imgur.com/a/DdQ4H9T
 
Sounds like you're set - I like shooting steel during this type of testing to verify that the bullet made it downrange.

I just looked at the powder burn rate chart. That CFE Pistol is a whole lot slower than Titegroup, I didn't know they were so far apart. It's still hard to say what's going to work better for you though, because there are so many variables.

I don't think it's come up here yet, but once you've found the lightest charge that will cycle the action, you might find that they give you terrible accuracy (possibly even keyholing). No problem, just work the charge weights back up until you get a load that groups well enough.
 
alpining said:
Sounds like you're set - I like shooting steel during this type of testing to verify that the bullet made it downrange.

I just looked at the powder burn rate chart. That CFE Pistol is a whole lot slower than Titegroup, I didn't know they were so far apart. It's still hard to say what's going to work better for you though, because there are so many variables.

I don't think it's come up here yet, but once you've found the lightest charge that will cycle the action, you might find that they give you terrible accuracy (possibly even keyholing). No problem, just work the charge weights back up until you get a load that groups well enough.
Click to expand...

Had a chance to test this out, mixed results:

Good News: The PC Carbine cycled everything and I had no exiting the barrel issues.
Bad new: Had some spotiness with my chrono so data is sparse, also had two light strikes. I've heard this can be an issue with magnum primers so I may have to change primers.

3.5g -> 826 fps, SD 40 (5 shots registered)
3.6g -> 839 fps, SD 26 (5 shots registered)
3.7g -> 888 fps, SD 22 (5 shots registered)
3.8g-> 904 fps, SD 36 (4 shots registered)
3.9g -> 928 fps, SD 23 (4 shots registered)
4.0g -> 973 fps, SD 6 (but only two shots registered)
4.1g -> Nothing registered.....

So from what I can tell all of these loads are clearly still subsonic. I might go on the hunt for standard SP primers and give it another go after trying to get my chrono a little more reliable too. I would say that all of these loads felt more gentle than factory loads so I will likely allow consistency dictate what load I end up with. I could notice the relative loudness difference of the handloads versus a factory supersonic round. More of a "confined thump" without that cracking noise. Quite pleasant to shoot.

I did notice that some of the brass was pretty sooty looking, I assume that's because the light load is not sealing the breech of very tightly on the lower charges.

For comparison against a random factory load in this carbine I ran six shots on S&B 124gr FMJ (my go-to plinking round) and got an average velocity of 1294 fps and a SD of 12 fps.
 
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CFE Pistol is pretty dirty, especially in light loads.
Ruger's bolt is a two-mass system with rather interesting kinetics.
I think it works better with faster powders.

6.5" barrel with brake/comp:
VV N320 - clean burning fast pistol powder - works fine with mid-range 124 gn loads (production pistol load PF ~130)
HS6 - slow, lots of gas to work the comp - no issues with reliability, but pretty harsh cycling in the blowback action. Tested with 115 gn RNHP running 1300-1500 fps in order to optimize ballistics for 100-150 m range.

N320+147 RNFP works well in FX9.
TG+147 RNFP could be a good combo.
I still prefer N320 because it burns cleaner and it is next to impossible to have a double charge.
 
JW85 said:
Had a chance to test this out, mixed results:

....
Click to expand...

Interesting. Pretty cool that everything cycles (though you haven't gone below published starting loads, right?).

I would for sure try it again with your Titegroup. As stated, the faster powder will probably work better for this.

Your SD looks pretty high across the board to me, or is that typical for your handgun reloads? Are you crimping much?

I wouldn't assume the magnum primers are the cause of your light strikes. First I'd rule out issues with primer seating depth and also clean the firing pin / channel and hammer / springs. These things run dirty... And yes, generally you'll see sootier cases with lighter loads.
 
alpining said:
Interesting. Pretty cool that everything cycles (though you haven't gone below published starting loads, right?).
Click to expand...

The loads were below the published Campro loads but not below the book values for 147gr FMJs in the Hornady Loading Manual.

These are actually my first handgun reloads and I agree the SDs seemed higher than I expected. I am crimping to what looked "reasonable" to me. I should get some pictures of the light strikes to show my crimp level and see if that's a factor. The charges were weighed on my Hornady G3 scale with lots of double-checking and testing some reference objects throughout the process so I'm confident the charge consistency was there.

I'll get some pics of the primer seating depth too and see if that's an issue. I haven't had a light-strike (or failure of any kind including FTE or FTF) through a few hundred rounds on the PC Carbine up til then.

I'm certainly up for trying Titegroup. I bought some in a powder buying panic with thin shelves at my suppliers. Was a little nervous due to the charge density of that powder but just need to be careful (as always of course).

Edit - Adding Photos:

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I have a theory that velocity variation at the low-end may be because the energy levels are low and thus variation in ignition reflects more clearly in velocity. Compared to high energy levels where a 50 fps variation in shot velocity is a larger relative energy differential. Pure speculation of course.
 
Can't be sure by eyeball, but the crimp *looks* grippy. Not much can be achieved on this front with 9mm anyway, I think. Higher SD may just be happening because we're dealing with light loads, which are especially variable with slower powders.

Appearance of the primers won't really tell us about proper seating depth - It's relative to the bottom of the pocket. Especially since they're magnum primers, you should be able to really mash em in there! ;)

But I'd still clean your firing system to eliminate that as a variable. Keep it very lightly lubed, like wipe down with a lube soaked rag, and it will stay cleaner a bit longer. Straight blowback is dirty dirty, and a few hundred rounds is right where I'd expect to start seeing buildup being a potential issue.
 
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