Kynshot Buffer question

[Fasthenk65]

Since some time available in Europe. I am using the 5007 with weight spacer and spring red spring with 124 plated RN @ 132PF and it is super.

 

Now dealer also has the 5015 HD in stock, following Kynshot website this one is better suited for 16" barrels?

 

Can somebody tell me the differences?

 

Thanks.

[zzt]

The HD model is built for stronger loads.  The hydraulic action is slower and the return spring stronger.   It is 'recommended' by some for 16" barrels because many want to use the same ammo in their pistol and PCC.  So a 132FP load for USPSA will gain 70-200 fps depending on the powder used.  To keep the buffer from slamming into the rear of the buffer tube, more resistance is needed for these 'hotter' loads.  I solved that problem by going to a 5.5" barrel with shroud.  So I can shoot the same ammo in my pistol and PCC and there is no (or very, very slight) PF change.

 

Since you chrono'd your load in your PCC and got 132 PF, you don't need it.  The standard buffer, 308 spring and short stroke slug are sufficient.  In fact, I'd suggest you at least try the 5.56 spring.  For 132 PF it feels a little better to me with the 5.5" barrel.  The 308 spring feels better with the 16" barrel.  I'm using fast powders so the velocity gain is not that great.

 

You don't say what you shoot, but I'll assume IPSC or falling steel, since you are at 132.  If you are trying for least dot bounce you will likely need to go higher,  144 PF with 147 gr bullets gives me no dot bounce.  I still use the same setup as you do; however, I'd go to the HD buffer if I was going to stay with those loads.  I only shoot SCSA and falling steel with my PCC.  I need 132 to knock steel down, otherwise I'd be around 120 PF for Steel Challenge.

Edited January 17, 2021 by zzt

[Fasthenk65]

6 hours ago, zzt said:

The HD model is built for stronger loads.  The hydraulic action is slower and the return spring stronger.   It is 'recommended' by some for 16" barrels because many want to use the same ammo in their pistol and PCC.  So a 132FP load for USPSA will gain 70-200 fps depending on the powder used.  To keep the buffer from slamming into the rear of the buffer tube, more resistance is needed for these 'hotter' loads.  I solved that problem by going to a 5.5" barrel with shroud.  So I can shoot the same ammo in my pistol and PCC and there is no (or very, very slight) PF change.

 

Since you chrono'd your load in your PCC and got 132 PF, you don't need it.  The standard buffer, 308 spring and short stroke slug are sufficient.  In fact, I'd suggest you at least try the 5.56 spring.  For 132 PF it feels a little better to me with the 5.5" barrel.  The 308 spring feels better with the 16" barrel.  I'm using fast powders so the velocity gain is not that great.

 

You don't say what you shoot, but I'll assume IPSC or falling steel, since you are at 132.  If you are trying for least dot bounce you will likely need to go higher,  144 PF with 147 gr bullets gives me no dot bounce.  I still use the same setup as you do; however, I'd go to the HD buffer if I was going to stay with those loads.  I only shoot SCSA and falling steel with my PCC.  I need 132 to knock steel down, otherwise I'd be around 120 PF for Steel Challenge.

tnx

I shoot IPSC

guess I leave it as it is