Sierra Matchking Bullets 300 AAC Blackout (308 Diameter) 125

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Fallschirmjäger
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by Fallschirmjäger »

20X11 wrote:
randyrucker wrote:The official word:

http://sierrabullets.wordpress.com/2013 ... -gas-tube/
ROFL...yeah, they group 2 completely different 125 gr projectiles together. AND they think H110 will handle a heavier charge than Lil Gun...not only do I doubt Sierra’s published data, I refute it based on my own empirical evidence.

So...not so "official" in my book.

And...now that I take a second look, they have a OAL that is less than the co-designer of the 2121 projectile recommends...completely bogus data, obviously RUSHED out the door to satisfy demand. Too bad they didn't do it right.

I doubt their loads for the 125gr matchking with Lil Gun will even properly cycle the AR platform.
I wasn't going to waste time posting this info until I read this thread looking for other loads to try.

I loaded up 70 rounds of 125 and 110 grain and went out Sunday morning to try out the Sierra data and here are some of the results:

Daniel Defense DDM4V5 16" w/ carbine gas system
CCI 450 Primers (yes, I know they didn't use these, but they're all I have, and I thought I'd be fine with the lighter loads)
Remington 223 brass, no crimp
Lil Gun powder
5 shots unsuppressed, chrony at 10'

Sierra 125 ProHunter, COL 2.000
16.0gr.: 2133, 2153, 2164, 2017, 2123 - First shot didn't cycle, so I loaded single rounds, and bolt did not hold open on any.
16.5gr.: 2002, 2030, 2026, 2080, 2189 - All had bolt hold back

Sierra 125 Matchking, COL 2.210
16.0gr.: 2038, 2020, 2038, 2060, 2002 - First shot didn't cycle, so I loaded single rounds, and bolt did not hold open on any.
16.5gr.: 2029, 2044, 1949, 2014, 2076 - All had bolt hold back, and had the best accuracy out of all the loads with this (although it still wasn't impressive).

I had 10 rounds of these 4 loads and shot the other 5 of each load suppressed without cycling issues, including on the 16gr. loads.

I'm pretty damn meticulous when I reload, so I thought the chrony (ProChrono) numbers indicated the chrono was toast, that is until I sent a number of shots across it using my air rifle (Air Arms S410 PCP) at the range and got accurate readings on the shots. To be honest the numbers left me so confused I didn't record the suppressed shots with the 125gr bullets because I didn't think there was much of a point. I checked each cartridge after firing since I was using the magnum primers and folks have mentioned pressure spikes, and there were no signs of any issues.

At the end of the day I'm going back to the Hodgdon load data but try the Sierra COL's. After I got back from the range I bought an RCBS Chargemaster combo from Natchez so I can load faster and not have to dick with the manual scale, although I know my charges were consistent. I was trying to use up the last of the Lil Gun I bought, but now that I have 4 lb's of WIN296 I'm going to start using that instead.
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randyrucker
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by randyrucker »

Ok so I went to the range today with some 125g SMK loaded with 18.5g or LIL Gun. Discounting two stringers group size was 0.42. Adding the stringers in group size was 0.79. Average velocity was 2081, SD 26.49. Overall I would say the groups seemed to be a little tighter for me than 18.0g. I am still at a total loss as to why my velocity is not more in line with what others are reporting for this load and bullet. It seems like I should be getting somewhere north of 2200 fps vs. 2018 fps with 18.5g of Lil Gun. Anyone have any ideas ? :?:
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randyrucker
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by randyrucker »

Anyone loaded the 125g SMK above 18.5g of Lil Gun? I want to get a little higher velocity but wondering about pressure.
tallburnedmidget
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by tallburnedmidget »

randyrucker wrote:Anyone loaded the 125g SMK above 18.5g of Lil Gun? I want to get a little higher velocity but wondering about pressure.
I do not, however I think I have seen evidence that when Lil'Gun is compressed you don't get much gain out of it. This is based off of my 130gr Barnes TTSX loading.

I think it is worth an attempt at increasing your OAL and seeing wht happens at 18.5.
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randyrucker
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by randyrucker »

tallburnedmidget wrote:
randyrucker wrote:Anyone loaded the 125g SMK above 18.5g of Lil Gun? I want to get a little higher velocity but wondering about pressure.
I do not, however I think I have seen evidence that when Lil'Gun is compressed you don't get much gain out of it. This is based off of my 130gr Barnes TTSX loading.

I think it is worth an attempt at increasing your OAL and seeing wht happens at 18.5.

Ok. I'm at 2.2 oal now. i'll try going to 2.26 oal and see what happens.
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by tallburnedmidget »

randyrucker wrote:
tallburnedmidget wrote:
randyrucker wrote:Anyone loaded the 125g SMK above 18.5g of Lil Gun? I want to get a little higher velocity but wondering about pressure.
I do not, however I think I have seen evidence that when Lil'Gun is compressed you don't get much gain out of it. This is based off of my 130gr Barnes TTSX loading.

I think it is worth an attempt at increasing your OAL and seeing wht happens at 18.5.

Ok. I'm at 2.2 oal now. i'll try going to 2.26 oal and see what happens.
It is my understanding that the minimal amount of bullet to safely have in a case is .200, so be sure you have this more or more in the case when increasing your COAL. I don't want you to have a bad day because I mentioned increasing the length of the round :)
20X11
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by 20X11 »

randyrucker wrote:Anyone loaded the 125g SMK above 18.5g of Lil Gun? I want to get a little higher velocity but wondering about pressure.
Yeah, I have gone to 18.8 grs...no pressure signs. Same accuracy as 18.5 with NO increase in velocity over 18.5. It seems the load hit a plateau for me. I would have no qualms about going to 19 grs in my guns, but I see no benefit over what the 18.5 is giving me...YMMV
Alien
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by Alien »

My most accurate loads for the Sierra 125 MK 2121 out of a 16" carbine gas 1 in 7.

17.8 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2109 fps (Very Accurate <.75 @100 yards )

18.0 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2060 fps

18.5 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2098 fps ES and SD numbers were crazy on this load accuracy went to 1.5.

I noticed with Lil Gun once you reach a certain point consistency goes out the window and your fps start going all over the place in my setup.


My best loads are with Alliant 300-MP.

19.0 gr 300-MP OAL 2.213 Comparator 1.516 Average 2203 FPS The Most accurate load in my gun.
This load shows light ejector marks use caution.
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randyrucker
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by randyrucker »

Alien wrote:My most accurate loads for the Sierra 125 MK 2121 out of a 16" carbine gas 1 in 7.

17.8 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2109 fps (Very Accurate <.75 @100 yards )

18.0 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2060 fps

18.5 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2098 fps ES and SD numbers were crazy on this load accuracy went to 1.5.

I noticed with Lil Gun once you reach a certain point consistency goes out the window and your fps start going all over the place in my setup.


My best loads are with Alliant 300-MP.

19.0 gr 300-MP OAL 2.213 Comparator 1.516 Average 2203 FPS The Most accurate load in my gun.
This load shows light ejector marks use caution.



Were did you get load data for 300 MP. I don't think I've seen it before.
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Chedr
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Re: Sierra Matchking Bullets 300 AAC Blackout (308 Diameter)

Post by Chedr »

randyrucker wrote:
Alien wrote:My most accurate loads for the Sierra 125 MK 2121 out of a 16" carbine gas 1 in 7.

17.8 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2109 fps (Very Accurate <.75 @100 yards )

18.0 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2060 fps

18.5 gr Lil Gun OAL 2.213 Comparator 1.516 Average 2098 fps ES and SD numbers were crazy on this load accuracy went to 1.5.

I noticed with Lil Gun once you reach a certain point consistency goes out the window and your fps start going all over the place in my setup.


My best loads are with Alliant 300-MP.

19.0 gr 300-MP OAL 2.213 Comparator 1.516 Average 2203 FPS The Most accurate load in my gun.
This load shows light ejector marks use caution.



Were did you get load data for 300 MP. I don't think I've seen it before.

YES PLEASE! I could sure use a starting point. Please. Using Sierra MK 125 #2121 and 300-MP with CCI-400 on a 16 inch barrel 1/8.
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