124 Peregrine Ballistics Gel Test
The goal of this study will be to find and record:
Consistency of diameter, length, weight, and Ogive of the projectile.
Complete load, workup.
At what point, the intended projectile will expand at its lowest velocity.
Report wounding channel effects of the projectile at various speeds i.e. Neck, Temp Cavity Length, Location of Max Temporary Cavity Diameter, Maximum Penetration Depth, and weight retained.
Report results of what the projectile will do at various distances through Clear Ballistics Gel block with Rib Bone.
Abstract
The 124 Peregrine VLR4 will expand at the lowest velocity between 1700-1800 FPS.
The current advertised 1:8 twist was not optimal for our lot of bullets.
It is important to record bullet diameter, Ogive, length, and weight when receiving a new lot of bullets. This will be potentially helpful for hunters when calculating if their bullet will produce pitching or yawing on game terminally. Moreover, it will also aid in calculating more accurate bullet stability. Diameter inconsistency can result in extreme spread spikes due to irregularities with diameter that is in relation with obturation.
Current stability with the advertised 1:8 twist, as we used, yields the following SG's: 1650 FPS: 1.15 SG, 1990 FPS: 1.22 SG, 2500 FPS: 1.32 SG, 2850 FPS: 1.37 SG. Which is marginally stable that produces bullet yaw and is ultimately not optimal for our lot.
A 1:7 Twist yielded the following SG's, which would be more optimal with our lot of bullets received. The results were: 1650 FPS: 1.50 SG, 1990 FPS: 1.59 SG, 2500 FPS: 1.72 SG, 2850 FPS: 1.80 SG.
The bullet itself has performed as intended regarding wound channel creation at low velocities. Further, it is not fair to say that the bullet is to blame because of the inadequate twist as advertised. The VLR4 is also offered in a 118-grain version that would be more optimal in a 1:8 twist.
Other variables like low temperature and altitude also play into the effect of how this particular bullet will perform. As designed in South Africa with completely different environmental factors.
"The 124 Peregrine, specifically the VLR4, is advertised as a high performance, BC enhanced, monolithic bullet designed for long-range use. Moreover, as a result of the BC optimized bearing surface, BC optimized boat tail, and BC optimized nose design, it can compete aggressively with any plastic-tipped monolithic competitor with the added bonus of low shot start pressure, low recoil, and increased muzzle velocity. The VLR 4 is designed to expand from 1600 FPS through medium and on to very high impact velocities of 3000 FPS. Further, the VLR4 has Perfect expansion as well as excellent weight retention which is achieved with the patented plunger initiator design. Unlike lead-core bullets, this bullet may be used for “on the shoulder (instant knock-down) shots”, instead of the limited option of only behind the shoulder. On the shoulder, shots are possible due to the solid copper bullet construction and the air pocket dampening effect of the brass plunger during nose expansion as strong bone structures are encountered. The brass plunger stiffness will prevent pre-initiation due to recoil forces acting on cartridges inside the magazine" (“VLR4 & VLR5 Ballistics").
Part 1. Consistency of diameter, length, weight, and Ogive of the projectile.
One of the things I look for in bullets is the consistency among them to what is advertised. Weight, length, ogive, and diameter are the four things I look at when opening up a new box to test or even compare my notes to other lots in the past. Let's dive in and take a look:
Currently, there is no data advertised for the length, Ogive, or diameter. Here we compare each bullet from the box of 100.
Diameter: The current results with my specific lot of the 124 Peregrines yielded a wider variety of diameters from bullet to bullet.
Length: The Length came in at a very consistent 1.42195".
Weight: Advertised at 124 Grains, I found the average to be 124.028. Again, very exceptional.
Ogive: The Ogive of the bullets came in at a wider variance than what we have tested so far with a Standard Deviation of the 100 bullets at 0.004.
Part 2. Load Workup for the 124 Peregrine As an avid user of Shooters World, I have found their powder, Long Rifle, to yield exceptional low SD, ES, and produce great results. If you had read my last article on the Match Burner and the LRX, I had mentioned that this powder also has virtually no muzzle flash. It is a short cut extruded powder, which ultimately works great in volumetric powder throwers because of it's kernel characteristics and properties. Plus, it is temperature insensitive in my testing of it.
Above is chart for those interested in the velocity results per charge weight. I opted for 44.2 grains of Long rifle that yielded me a 2858 average with an SD of 7 and an ES of 13 from a 10 shot group. After finding this great load, I decided to put it to paper.
10 shot string, 5 warm-up shots taken beforehand. I was able to produce a .689 inch group. .689-.264=.425" grouping. Not too bad!
Use load data at your own risk. Reloadingallday is not responsible for errors with load data on this website.
Please keep in mind, the suggested maximum powder charge weight, according to Shooters World, is 42 grains with a 130 TMK going 2774 FPS. If you do copy my load data, please workup in very small increments and be aware of any pressure signs that might show with your reloads. In this case, depending on where you are in relation to your lands, it can drastically change your pressure. Velocity is also affected by temperature and other components including barrel length.
What components were you using, barrel length, build, etc?
Reloading gear
1. Forster Coax
Brass was prepped as explained here, 2.178 CBTO, brass is 3 times fired annealed with Amp Induction Annealer each firing.
Rifle
This rifle was built by Rick over at GCP Rifle Co. It shoots light out and is getting great speeds for a 16.5" barrel. My main load is using 120 SMK's with CCI 450's, Lapua brass SRP, and the SW Long Rifle Powder is yielding 2850 fps for my worked up load.
I pulled the fifth shot. Besides my mistake, it can shoot.
Was also fortunate enough to harvest a buck on the last day of the season with the 124 Peregrines at 210 yards. impact in the spinal column and instantly dropped.
Now, before we get started, I want to explain how I measure these gel blocks.
1. Neck: As the bullet enters, measure when the bullet starts to expand.
2. Temp Cavity Length: How long the cavity length is inside the gel block itself.
3. Location of Max Temp Cavity Diameter: How wide the biggest point is inside the cavity channel.
4. Maximum Penetration Depth: How long the bullet penetrated from entry to final stopping point.
5. Bullet: Weight retained after gel block test is complete.
Moreover, I now try and find the breaking point of the projectile from when it fragments to when it mushrooms by lowering the velocity of each round to give you an idea of what to expect your projectile to do downrange at further distances.
Side tip: Take the data that you see below; Based on your muzzle velocity of your handloads, with the 124 peregrines, you can reasonably expect what your bullet will do, terminally, on game at distance. Please use a reputable ballistic calculator for the most consistent results
Part 3,4,5. 124 Peregrine Gel Block Results Below:
25.5 grains, 1631 FPS MV, shot taken at 50 yards. 12:13 AM, 40 F, 89%, 29.15, alt: 955ft.
1. Neck: As the bullet enters, measure when the bullet starts to expand.
3/4" Approx
2. Temp Cavity Length: How long the cavity length is inside the gel block itself.
3 1/4" Approx
3. Location of Max Temp Cavity Diameter: How wide the biggest point is inside the cavity channel.
2 1/2" Approx Location. 1 1/2" Approx Wide.
4. Maximum Penetration Depth: How long the bullet penetrated from entry to final stopping point.
12 3/4" Approx as the bullet exited from yawing.
5. Bullet: Weight retained after gel block test is complete.
No bullet recovered due to yawing
After reviewing the gel block, we started to notice yawing...which we will explain at the end of the article. Moreover, the projectile tip itself had stayed intact and created an extra wound channel of its own. No fragmentation. Bullet has not "expanded" yet at this velocity.
2. 28.0 grains, 1873 FPS MV, shot taken at 50 yards. 11:40 AM, 40 F, 74%, 29.16, alt: 955ft.
1. Neck: As the bullet enters, measure when the bullet starts to expand.
instantaneous
2. Temp Cavity Length: How long the cavity length is inside the gel block itself.
5" Approx
3. Location of Max Temp Cavity Diameter: How wide the biggest point is inside the cavity channel.
4 1/2" Approx Location. 1" Approx Wide.
4. Maximum Penetration Depth: How long the bullet penetrated from entry to final stopping point.
10" Approx as bullet exited from yawing. Bounced back into gel block and stopped at 14 1/4" Approx.
5. Bullet: Weight retained after gel block test is complete.
117.45 Grains
After reviewing the gel block, we still noticed a trend in yawing. Moreover, the projectile tip itself had stayed intact and created an extra wound channel of its own. No fragmentation. Bullet has "expanded" at this velocity. It is important to note, now, that the minimum velocity required is now benchmarked between 1700-1800 FPS
3. 30.0 grains, 1993 FPS MV, shot taken at 50 yards. 12:49 AM, 43 F, 87%, 28.79, alt: 955ft.
1. Neck: As the bullet enters, measure when the bullet starts to expand.
Instantaneous
2. Temp Cavity Length: How long the cavity length is inside the gel block itself.
6 1/2" Approx
3. Location of Max Temp Cavity Diameter: How wide the biggest point is inside the cavity channel.
4 1/4" Approx Location. 1 1/4" Approx Wide.
4. Maximum Penetration Depth: How long the bullet penetrated from entry to final stopping point.
14" Approx
5. Bullet: Weight retained after gel block test is complete.
113.15 Grains
After reviewing the gel block, we again noticed the trend in bullet yaw. The projectile tip itself had stayed intact and created an extra wound channel of its own. No fragmentation.
Bullet Yaw
As you have seen, we noticed the trend of bullet yawing with the 124 Peregrines. After inspecting, we found what was going on.
The 124 Peregrine VLR4 is currently advertised as a 1:8 Twist. After putting our specific lot information into Berger Bullets Stability calculator, we found the following information below:
1650 FPS: 1.15 SG
1990 FPS: 1.22 SG
2500 FPS: 1.32 SG
2850 FPS: 1.37 SG
What this means is that the bullet is only marginally stable at the lowest velocity, and the highest velocity as well.
"Stability is quantified by the gyroscopic stability factor, SG. A bullet that is fired with inadequate spin will have an SG less than 1.0 and will tumble right out of the barrel. If you spin the bullet fast enough to achieve an SG of 1.5 or higher, it will fly point forward with accuracy and minimal drag. SG’s between these two extremes represent bullets flying in ‘the gray area’ of marginal stability. Bullets flying with SG’s between 1.0 and 1.5 are marginally stabilized and will fly with some amount of pitching and yawing. This induces extra drag and reduces the bullets effective BC. Bullets in this marginal stability condition can fly with good accuracy and precision, even though the BC is reduced. For short-range applications, marginal stability isn’t an issue. However, shooters who are interested in maximizing performance at long range will need to select a twist rate that will fully stabilize the bullet, and produce an SG of 1.5" or higher" (https://bergerbullets.com/the-state-of-the-art-in-rifle-bullet-stability/).
As we dug further into the information, we simply changed the 1:8 advertised twist in the calculation to a 1:7 and found the results below.
1650 FPS: 1.50 SG
1990 FPS: 1.59 SG
2500 FPS: 1.72 SG
2850 FPS: 1.80 SG
As a result, the 124 Peregrine would be better suited with a 1:7 twist, with the current bullet design rather than the 1:8 as advertised. Furthermore, bullet performance in itself showed very good wound creation at lower velocities. Using a 1:7 twist barrel would show even better results in regard to maximum penetration, temporary cavity length, Location of maximum temporary diameter, and maximum penetration depth. As a fair assessment, our altitude and weather conditions are massively different from that of South Africa where these bullets are designed. To say conclusively that bullet yaw was directly due to the inadequate amount of twist would be incorrect. Ofcourse, there is many things that we may have not realized and made mistakes. This projectile is still very well made and constructed and I would recommend it for use on game.
Thank you for reading! If you are interested in learning how to reload or are an experienced handloader looking to learn how internal ballistics works to significantly cut down on load development time you can find our classes here
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