<< Previous Topic | Next Topic >>  

Review of the Redesigned .177 JSB Monster pellet

December 2 2017 at 7:21 PM
Philip Hepler  (Login phepler)
YF12

Here's my unscientific review of the "Redesigned" .177 Monster pellet from JSB.
After waiting for months while my order of the new design Monster was on back order, I finally received a couple of tins and did a little comparison of the original vs. new design.

[linked image]

I first weighed individual pellets from both designs. Similar to the original design pellet, only around 30% of the redesigned Monster pellets in the tin were actually 13.4 gr. Some were heavier or lighter give or take a tenth of a grain. That may not be a big deal, but just for consistency I only used 13.4 gr. from both the original and new design for this test.

[linked image]

The change of pellet shape from old to new is obvious, but the skirt of the redesigned Monster looks identical to the original. The redesigned tin of pellets I sorted seemed a bit dirtier than the original design tin I sorted, as my fingers were dark gray by then end of handling 400 pellets one by one.

[linked image]
[linked image]

Off to the sight in range! Weather was overcast with practically no wind and temperature around 54°. I'm testing these pellets with a non-regulated Gen 1 Marauder with a LW barrel, from a table with a bipod attached. I use this rifle for Hunter Field Target so it’s tuned to around 20 FPE. My scope is a UTG 12x, and I did not adjust or click my scope in any way during this test. I recorded the velocity of each shot of my groups shot at 55 yds. Before shooting each group of pellets I filled the gun to 2700 lbs. First I shot a small group at my 25 yd. zero with each type of pellet. As you can see, the original Monsters were on zero, and the new designed Monsters shot a bit lower- about 1/4" lower. I noticed the new design pellet fits a bit tighter in the breach than the original.

[linked image]
[linked image]
[linked image]

At 55 yds I filled the rifle back up to 2700 lbs. for each group. I shot two, 10 round groups of each pellet design at 55 yds. As you can see, my best group from the original design pellet was slightly better at 7/8", but I had a couple of fliers that I can not explain. The redesigned Monster group was 1".

[linked image]

The velocity from each group was similar and I didn't see a big difference there.

[linked image]
[linked image]

So what are your thoughts? Which would you use?
Next step will be to test my grouping of original Monster vs. new Monsters in the wind.

Thanks for reading,
Philip Hepler
Member of the Tar Heel Air Gun Club- hosts of the 2018 AAFTA Field Target Nationals


    
This message has been edited by phepler on Dec 2, 2017 7:59 PM


 
 Respond to this message   
AuthorReply
gubb33ps
(Login gubb33ps)
YF

Been dreading that...

December 2 2017, 9:57 PM 

Thanks for the write up.

Have been kind of dreading the "improved" version. Have a couple of .177's that really shoot well with the "old" version, and sure-as-ship, the old version is going to be replaced with the new.

Hopfully, the differnce won't be disproportionate.

 
 Respond to this message   
Terry E
(Login TleVta)
YF12

Do the new ones

December 3 2017, 12:26 AM 

fit better in your magazines? Can't tell in your photo if you're using a shot tray in your gun.

The originals will catch the holes in the clear plastic with the skirt edges.

 
 Respond to this message   
Philip Hepler
(Login phepler)
YF12

Redesigned JSB Monster in magazine

December 4 2017, 8:47 AM 

I only use the single shot tray when as I only shoot Field Target. I have used the mag in the past with monsters so I know what you mean. I've used a ball point pen to push them into place. I just tried it and these new designed pellets have a similar fit in the mag, but for me it's not so much the clear cover that catches them as much as the skirt size has a hard time fitting the in magazine holes. Some holes/pellets must me larger/smaller because some pellets will slide right in, where others will not clear the plastic cover. I've seen youtube videos of how to modify your magazine holes with a drimel tool to make them slide right in.

 
 Respond to this message   

Billy Dick
(Login ocedummy)
YF12

Weighting is good but head size is better.

December 3 2017, 12:50 AM 

Shooting groups with different head sizes would be better. For example, my Poly barrel TM likes 4.53 better than 4.52.

 
 Respond to this message   
Philip Hepler
(Login phepler)
YF12

diff head sizes

December 4 2017, 8:49 AM 

I don't disagree, just haven't purchased a head sizer yet and started that habit!
some think I'm crazy for going to the trouble to weigh them, but I've seen some as light as 12 grains and I would hate for that to cost me a shot on the Field Target lane.

Thanks
Philip

 
 Respond to this message   
Will Piatt
(Login saddlemountaingunsmith)
YF

Nice work Phillip

December 3 2017, 7:20 AM 

To determine which pellet to use shoot twenty 5 shot groups with each, carefully measure the groups and get an average group size for each pellet. Interesting on the targets you pictured it appears original strings vertically and the new horizontally.

 
 Respond to this message   
Jason
(Login nervoustrigger)
YF12

Barrel whip?

December 3 2017, 10:19 AM 

Could explain the vertical stringing but it doesn’t generally cause horizontal so I’m not sure what to make of it unless the wind conditions happened to be worse when shooting the new Monsters.

I never tried the .177 Monsters due to how awful the .22 were. Just a couple of days I ordered some of the redesigned pellets in both calibers to try out so I’m looking forward to that.

 
 Respond to this message   
Philip Hepler
(Login phepler)
YF12

Will do

December 4 2017, 8:51 AM 

Good idea. I'll try that.
Also want to try each in wind.
I didn't notice the horizontal vs vertical- that is interesting.

thanks
PH

 
 Respond to this message   

Dutch
(Login Dutch.22)
AR&P

Wonder How They Would Do At 23 fpe

December 3 2017, 7:39 AM 

out of my Rapid. Very interesting..

 
 Respond to this message   
Chris
(Login bladesx)
AR&P

Re: Review of the Redesigned .177 JSB Monster pellet

December 3 2017, 11:36 AM 

As with rimfire chamber size , bore dia, Twist, and velocity all come into play.

 
 Respond to this message   
Jason
(Login nervoustrigger)
YF12

Factors at play

December 3 2017, 12:15 PM 

True but at the same time, consensus is these factors tend to be less important with pellets. Probably the clearest practical example is twist rate. A flare stabilized projectile (diabolo pellet) doesn’t need much spin to fly straight. The extremely slow rate of twist delivered by a Smooth Twist is a good example.

The pros say the chamber / leade is less critical dimensionally and geometrically.

The role of velocity is less clear. Some have experimented with running the longer pellets like the Monsters over a wide range of velocities without a clear pattern emerging. If memory serves, the most compelling report I’ve seen was regarding a Thomas shooting them around 800fps in a much slower twist, and doing so well enough to win a competition. That runs counter to rimfire logic where the longer projectile benefits from a faster twist rate.

Lastly, even sizing is less critical. The skirt obturates to form a seal and as long as the head rides the rails, to borrow yrrah’s phrase, it seems the resulting accuracy is often quite good. He put up a nice experiment where he downsized pellets quite a lot before accuracy diminished. Again from memory, I think it was below 4.47mm which by most would be considered unacceptably undersized. Surely not all barrels would be as tolerant to the same degree but it does call into question the conventional wisdom regarding head sizes.

With that said, put all those in a blender with some barrel harmonics and a dash of wind and who can tell what’s important? happy.gif




 
 Respond to this message   
Andrew
(Login yinyout)
YF12

Indeed Sir. Nice summation my friend! Nft

December 3 2017, 1:59 PM 


 
 Respond to this message   
Miles
(Login Miles_M)
YF12

It's nice to see

December 4 2017, 4:23 PM 

someone correctly refering to a diabolo as flare stabilised, which is correct, as opposed to drag stabilised, which it isn't.
As for twist rates and speeds, my calculations suggest that as a diabolo pellet's speed gets near to the speed of sound the aerodynamic stability decreases at a fairly high rate until it becomes aerodynamically unstable around Mach 1. As a result the twist rate needed for stability will increase as the speed approaches Mach 1. Below about 850-900 ft/sec the aerodynamic stability seems to remain fairly constant and needs much less spin.

 
 Respond to this message   

Joe Brancato AirTanksForSale.com 714-907-0067
(Login n6yyo)
YC

Very nice write-up. Thank you

December 5 2017, 9:45 AM 

Very nice write-up. Thank you for posting.

To receive notifications of the latest Airgun and How-To videos, and discounts and updates on my products, please "Like" my FaceBook page at
https://www.facebook.com/AirTanksForSale


Joe Brancato 714-907-0067

For AirTanks, Custom Hoses, Fittings, Gauges, etc.
please click here http://www.AirTanksForSale.com

[linked image][linked image]

 
 Respond to this message   
Raymond Hawkins
(Select Login rhawk1)
YF12

Very Interesting

December 6 2017, 6:33 PM 

Philip,

Good job on the review and very interesting as well. I typically shoot the 10.34 but to be honest I've never tried the monsters. Now that I've finally gotten my rifle and I shooting at it's best, temptation got the best of me. I ordered a tin of the Monsters last week but didn't realize there was still an option. Anyway I'm curios to see how they perform in the wind verses the 10.34's. With so much time invested in my current choice I'm hoping the monsters don't work.

Raymond Hawkins

 
 Respond to this message   
 
  << Previous Topic | Next Topic >>  

Airgun Calculators    Num of fills calc    Capacity Calc

******** Kalibrgun High quality, superb Accuracy, outstanding Value. ********





D I S C L A I M E R
JK's Airgun Forums, moderators, and administrators are not responsible for any problems that may occur from reading or using content posted on this forum, as they are the exclusive responsibility of two parties: the person who posted it and the person who acted on said posted information.Use of our forums by people under 18 years old is allowed only with legal guardian(s) present.